Based on other posts of where you were, here's what you need to catch up. First, the simple, TF-centric version, by trade paperback where possible:
- Revolution
- Till All Are One vol. 2
- Revolutionaries vol. 1 (optional)
- Till All Are One vol. 3 but bookmark it after TAAO 12
- Optimus Prime vol. 1
- Optimus Prime vol. 2
- Revolutionaries vol. 2 (optional, but really good)
- First Strike (may be branded as "Transformers / G.I. Joe First Strike")
- Transformers: Salvation (one-shot, "Annual" sized issue)
- Optimus Prime vol. 3
- Go back to your bookmark in TAAO vol. 3 and finish it
- Optimus Prime 2018 Annual (one-shot)
- Optimus Prime vol. 4 (not out yet as a trade, but this is OP 15-21)
- Transformers vs Visionaries (or read a summary, imo it's not very good)
- Requiem of the Wreckers (one-shot, "Annual" sized issue)
- Now you're caught up to the Unicron series, see towards the end of the lengthy list below for a suggested order
Now for the "literally everything except Lost Light (since you already mentioned that) since ~2 years ago" by individual issue. Probably a few repeats for you, I copy/pasted it. Note that this is not an
official reading order, but it should work. Also includes some newly retconned to be "in universe" material and all Hasbro U stuff, just in case!
1 - Pre-Revolution - these occur prior to Infiltration #0 but after Shockwave has initiated Regenesis. Exactly where? That's up to your imagination on the first couple entries.
- Rom: Annual
- Rom vs Transformers: Shining Armor 1-5
- Hearts of Steel mini-series (optional, in my opinion)
- Infestation 2 mini-series (also optional, in my opinion. For this and the above, extra/back-matter in Revolutionaries will fill in the gaps!
2 - The Road To Revolution and Titans Return- Hasbro Heroes Sourcebook #1 - "Roadies" opening short
- Transformers 50 - 55 ("All Hail Optimus"/Volume 10 TPB)
- Till All Are One 1-4 (Volume 1 TPB) - roughly concurrent with "All Hail Optimus"
- Micronauts 1-6 (Volume 1 TPB) - could really go anywhere before Revolution, because Time is All Things. I think it gives a satisfying real-life-reading-time gap in between some of the TF stuff going on here, making the transitions less jarring. YMMV
- Titans Return One-Shot
- Transformers 56-57
- More Than Meets The Eye 56-57
- First Strike #0 (Not a typo! Not the most satisfying place to read this but if you're looking for chronology, well...)
- Revolution #0
- M.A.S.K. Revolution - Rough guess with this being ~ a year before Revolution, but it would need to be after Blitzwing's capture.
- Rom #11-14 backup story "Tales of the Solstar Order"
- Rom #0
- Action Man #0-4
- Rom #1-4
3 - Revolution- ROM Revolution
- Revolution #1
- Revolution #2
- Micronauts: Revolution
- Till All Are One: Revolution
- Revolution #3
- G.I. Joe: Revolution
- Transformers: Revolution
- Action Man: Revolution
- Revolution #4
- Revolution #5
- More Than Meets The Eye: Revolution
4 - ReconstructionA list isn't the best representation here as there are a great deal of things happening
more-or-less concurrently. YMMV, this list is what I like and it purposely jumps around to different things just for the sake of it at times.
- G.I. Joe #1-4
- M.A.S.K. #1-5
- Till All Are One #5-8 (Volume 2 TPB)
- Micronauts #7-9
- Micronauts Annual
- Micronauts #10-11
- Hasbro Heroes Sourcebook #2 - "Upgrades" opening short
- Revolutionaries #1-3 (Issue 1 occurs before Rom #5, Wrath of Karza is after issues 2 and 3)
- First Strike #1 backup story "The Origins of Evil, Part One: Redcliffe Club" (Probably. It's all messed up so... this feels good enough. Different contextual clues put this in different places, but it seems to work pretty ok here and it will remind you of some folks existing amidst other things going on.)
- M.A.S.K. Annual
- First Strike #2 backup story "The Origins of Evil, Part Two: A Game of Chess"
- M.A.S.K. #6-7
- Till All Are One #9-12
- Rom #5-14 - Not including the "Tales of the Solstar Order" story (This could be split up, but I'm not comfortable suggesting you have to for these purposes)
- Wrath of Karza #1-5
- First Strike #4 backup story "The Origins of Evil, Part Four: Hitting the Big Time"
- Revolutionaries #4-6 (issue 4 takes place sometime after Wrath of Karza, issue 6 is sometime after MASK #6)
- Optimus Prime #1-8 (Optimus Prime issue 7 is stated to occur roughly a year after the events of Transformers #50-55, "All Hail Optimus")
- Transformers Annual (2017)
- G.I. Joe #5-9 (I guess, nothing really jumps out as placing it here but it has to go somewhere)
- M.A.S.K. #8-10 (It has to go somewhere and I like putting it in before Revolutionaries wraps up.)
- Revolutionaries #7-8
- Optimus Prime #9-10
- First Strike #3 backup story "The Origins of Evil, Part Three: A Little Bit of Mayhem"
- First Strike #5 backup story "The Origins of Evil, Part Five: One Unholy Machine"
5 - First Strike- First Strike #1
- Optimus Prime First Strike (events occur concurrently with First Strike #1)
- Optimus Prime #11 (events occur concurrently with Optimus Prime First Strike)
- Micronauts First Strike
- Rom First Strike (This and the Micronauts story basically stand alone with little else to do with the First Strike event, so may as well get them out of the way before the really interrelated stuff hits the forefront of the plot.)
- First Strike #2
- First Strike #3
- Optimus Prime #12 (events occur concurrently with First Strike #2-3)
- G.I. Joe First Strike
- M.A.S.K. First Strike
- First Strike #4
- Transformers First Strike (events occur concurrently with First Strike #2-4)
- First Strike #5
- First Strike #6
6 - The Road to Unicron- Rom and the Micronauts 1-5 (kinda just runs parallel to other stories, can really go anywhere within this subset of books)
- Transformers: Salvation
- Optimus Prime #13-14
- Till All Are One Annual
- Optimus Prime Annual (this starts before the TAAO annual, but ends after.)
- Optimus Prime #15-16
- Scarlett's Strike Force #1-3 (#2 references the Ore 13 mine opened up in KY during OP #15)
- Optimus Prime #17-21
- Transformers vs Visionaries #1-5
- Requiem of the Wreckers
7 - End of the Road- Optimus Prime #22 (pages 1-13)
- Unicron #0
- Optimus Prime #22 (pages 14-20)
- "Ad Infinitum" - back up Rom strip published in Unicron #1
- Unicron #1-3
- "Last Stand" - back up G.I. Joe strip published in Unicron #2
- Unicron #4
- Optimus Prime #23 (mostly concurrent with Unicron #4)
- "Reunion" - back up M.A.S.K. strip published in Unicron #3
- "Transition" - back up Micronauts strip published in Unicron #4 (not actually sure where this goes yet, except "after Unicron 1")
Rodimus Prime wrote: I was kinda hoping TAAO would do that since it seemed to put the Combaticons in the spotlight, but all we got was some PC fanservice and a half-hearted story of manipulation. That's why I said before that it could have been so much more. Unfortunately IDW doesn't have the writers with enough skills to pull it off.
This sure is an opinion.
TAAO is fantastic and you should ignore most everything RP says about it here, imo