So because this doesn't have a "Suggestions" discussion I decided to make one myself, starting with a few of my own Ideas I had but lack any sort of skill needed to make a sub-mod of my own. And these ideas probably would need to be a sub-mod.
Note that my ideas are often wildly beyond what is "reasonable" or "possible" so take any I make with a grain of salt and a lot of "would that even work?" questions. I have a habit of just "throwing ideas at a wall and see what sticks" when I brainstorm, especially if I actually like the thing I'm brainstorming about, be prepared for wild and impossible ideas.

Potential Ideology functionality, Dragon Ideoligion, likely a very high impact and possibly multi-part in functionality.

Potential Royalty functionality: Dragon-based meditation(possibly connected to the Ideoligion) with a possible option for a unique "royalty" tied to a specific pawn, and their kids, being "blessed" by the dragons that the ideoligion worships, being bonded to the dragons, being considered the leaders, etc.

Potential Biotech functionality: Interconnection with the others, possibly have it where kids can be "bonded" to a hatchling via a ritual, resulting in a bond going significantly deeper than usual and granting the child a free Psylink(or what have you) alongside their Dragon partner being given some kind of buff as well(possibly making it perma-tame, free training, etc)
Additionally, a possible blood-line thing ala Game of Thrones that give the pawn some level of fire and heat resistance, as well as potentially being the only ones able to tame true dragons or something equally fitting for a "dragonblooded" gene.

Potential alterations to make it so that Dragons, or at least just True Dragons, are intelligent enough that they are not animals in the game's terms, but rather something between animal and pawnkind, not able to do things "normal" pawns can as they simply work off of different mentalities(can't negotiate, but can give a negotiation buff to their linked pawn because having a big ol' dragon acting as the big stick to your speaking softly is a very heavy incentive to just nod at whatever you say), but still being more capable than animals can be even with lots of other mods(able to act entirely on their own, able to interact with pawns on a much more even footing as they are supposed to be at minimum as intelligent as most pawns, able to do various jobs animals simply can't).
End result being that the Dragons are something of their own thing, standing on their own alongside other "major features" such as some of the "factions expanded" mods, mechanitors, etc. with an entire alternative playstyle revolving wholly around the dragons themselves. Would be comparable to a DLC or major mod in their own right, if one that's possibly small in volume of content.

And before you ask this "alternate playstyle" idea, based in using features from literally every DLC so far, is somewhat inspired by the same idea behind "themed" runs or things like the factions expanded/the new mechanitor playthroughs. A sort of "You can do other things, but this is the center of your playthrough" idea that you could make an entire youtube series centered around it(and if my ideas aren't impossible and one day someone like mister streamer actually does this I'll consider it the ultimate win, because as far as just being the "idea guy" nothing can really top your wild ideas actually being made real).