Hi Beryl. Been playing this game since approx version 0.4.0 and have been obsessively keeping track of updates. You've turned what could have been an extremely repetitive TF lootbox into a high stakes contest of wit and skill. Unlike some other TF games it's pretty difficult, too! I admit that the first couple playthroughs I had to resort to savescumming to figure out how to get some endings without being transformed in ways I didn't want - which is exactly what the game is designed to do to all the characters playing it.
This has been suggested before, and I know it's on your to-do list, but I'd still like to echo my support for the Experience or some sort of age progression transformation. Could create some sort of paired mental transformations to go with it, e.g. Longanimity, making the characters inwardly more mentally mature, struggling to use technology, more stoic and grumpier.
Another suggestion would be a physical transformation for conventional attractiveness, and with it a mental transformation of vanity or narcissism, e.g. Majesty for sharper jawlines, striking features, statuesque beauty; and Ostentation for an obsession with the current physical form of the character, making them more resistant to change and reacting much more strongly to any physical transformation but very quickly becoming used to their new form and becoming self-obsessed once more.
Finally to round out the list, would love some sort of himbo combination with Fatuity + Muscle + another transformation. Dumb, good natured, buff, horny. Need I say more.
I write on the GSS as imperatenor. Would love to contribute some writing for endings or transformation sequences if you feel my style is appropriate!