Zyuran could get a remold of Super Zenkaiser, while Magine gets a remold of Twokaiser's SD form.

Magine forming the head of the resulting combination could also be a reference to how the one part of Magiking she didn't already turn into is the part that forms the head, with the other pieces being represented by her Dragon form.

Yeah. Magine's Color is based upon the fact that MagiFairy became the head of MagiDragon, but MagiTaurus actually is where the head of MagiKing comes from (they share the head).

Though, I say that, as long as Super Zenkaiser and Super Twokaiser SD aren't gang molded, I say that a Remold of Super Twokaiser SD could be turned into Super Stacaesar SD (for a super form based upon Abaranger and Fake GokaiOh). Summoning Black CrocoDaiOh and Black TwokaiCutanner, he becomes Black TwokaiOh.
Another idea is them being put against "Mirror World", a World monster which can summoned Mirrored Versions of the Zenkaisers, sort of like Copy World, except with recycled suit parts from Noon/Sun World (the Staff) and a remolded Door World base suit to look like a mirror. The World monster and these fakes would later turn on Tojitendo and cause the Summoned Fakes to combine into ZenkaiOh JuraJuran, VrooVroon, MagiMagine, and GaoGaon. This would overall be a more comedic episode. Wishful thinking, but who knows?

I do hope we get to see the fight against SD World, and the implications that has for the World Pirates.

I personally really want the Legend Sentai Gears in Kikai Side are used when Kaito dan Zox piloting their robots. Maybe ZenkaiOh and TwoKaiOh can be access previous Super Sentai Robot finishers if Kikai Side are used in the ZenkaiOh cockpit and TwoKaiOh cockpit.

The four robotic Zenkaigers could probably also use the kikai sides of the gears themselves when they're giant, but haven't combined.

We know they have the Gaoranger gear, so they could easily have Gaon fire a laser in the same way GaoKing did.

Also, according to this source: https://www.ladyeve.net/archives/073058 (can't tell if this is true as I don't speak Japanese. Only knowing this because of the wiki), apparently, Kikai Sentai Zenkaiger was originally going to be called "Sentai Sentai Sentaiger. Which sounds like someone's alternate name for Gokaiger if they didn't know any of the names. And is extremely funny to think about. It's a major tongue twister. Kikai Sentai Zenkaiger was named Sentai Sentai Sentaiger.

That's awesome. It would've fit well too!

What is interesting is that Battle Fever J was created with the mindset of trying to make a live-action Combattler V.