
The support is there but it depnds on how new your Armada/Micron Legend Jetfire is. The photo I took was from a used Armada Jetfire. I recently aquired a Micron Legend Jetfire that was used but 100% complete. Though I haven't took pictures he was a lot sturdier combined with ML Jetfire.
The main thing to remember is connecting Overload just right to Prime. The insides of the cab fists that point up when Prime is transformed in Super Mode lock into place where the tabs are on Overload when in combined cannon mode. This is probably the studier part of the combination. Even combined with the "trailer pants" he may topple over. When this happens, the Cab in super mode and Overload cannon mode stay together no matter what.
What sucks about Jetfire as pants is he turns real skinny. To make it truly work you have to understand how to place the wings and feet. With the combined Overload cannon you have to keep them close together, or yay wide apart in the picture I took. It can be done, and heck it's supposed to be done.