That would be an interesting fanfiction. GI.Joe is chosen for an ultrasecret mission to cross a "stargate" and they travel to an alternate earth, Gamma World, but if the native menaces and the arrival of Cobra squads, also there are also other visitors from the D&D multiverse, and the Phyrexians from Magic: the Gathering, with some magitek vehicles from Kaladesh.
And Optimus Prime kicking-ass Inhumanoids, those kaijus from a forgotten Hasbro's franchise.
* The battlemechs, the mechas from Battletech franchise usually are 8-10 meter talls. This is close to size of D&D giants and cybertronians/transformers.
I wouldn't be the D&DB forum moderators if players start to chat about what mechas are more powerful, if from Battletech or Robotech.
* GI.Joe use tech from 1980'-2020y. They couldn't face easily technology from sci-fi franchises, but now I am thinking about a G.I.Joe-Star Wars mash-up, I don't mean a crossover but new "universe" mixing things from both. Why? Because the speculators would buy the limited edition toys to be sold later to collectors. (Don't fool me, now you are imagining Snake-Eyes and Storm-Shadow fighting with light-sabers!). There were Star Wars - Transformers toys in the past.
Or mixing Robotix with a softer version of Dark Sun. We have the classic spaceship or spelljammer crashed in a dessert planet, and this caused the restart of a forgotten war between biopunk mecha-like creatures, created when somebody tried reverse ingeneering from a cybertronian corpse.
....(and how would be virtual miniatures of Transfomers-Star Wars or any other collab?)
* And what if a pack was a life-simulation game like the sims, with a lot of social interactions, perfect to produce machinimas videos? This life-sim game could be played totally offline after be downloaded and installed.
And some streamer producing a machinima soap opera set in Cerilia/Birthright.. (and with a secret, one of the main characters is an isekai, a reincarnated from other world. Really it is her third incarnation, first in Cerilia, second in Gamma World and the third in Cerilia again. Other character is a psionic ardent because in her previous life she was a cleric of a deity from other wildspace.