@RunRudolf amazing update! I love the new expression morphs feature, it's very cool and adds a lot. Exactly what I had in mind. The pulsing morphs look GREAT too - you nailed it. Fantastic work, thank you so much!
I do have one other idea as I've been playing with it. Your solution for hiding/undressing with the sort of 'tuck and unfold' is great. But there are some underwear pieces for both males and altfutas that do have enough room for the penis to fit without clipping when it's flaccid. Clipping is worst when the penis is erect because the cloth can't exert any forces on it, so it stands straight out from the body and the clothing has to 'stretch' with it. It seems like you have something going on in REF that forces the penis to but 'tucked' up against the body whether flaccid or erect, then 'undress' triggers the 'unfolding'. It's a great effect as-is. But - what I'm wondering is if we could have the option to still do the 'tuck and unfold', but NOT hide the gens material. So when the clothing item is attached, the penis is 'tucked' whether erect or not, and only unfolds when undressing, but is still technically visible. This would be nice with underwear or bottoms that have enough room for a flaccid penis, but have clipping issues with erections. You'd get the benefits of sim clothing that could bulge more when the character has an erection, but have far fewer clipping issues since the erection wouldn't be pointing straight out. Just having 3 checkboxes instead of 2 would do the trick - right now it's Hide Material and Sim Undress, you could just add one called 'Tuck Penis' that would activate your system exactly as-is but not hide the gens material. Then the user would have the power to use the system but choose whether or not the material is hidden.
That's my final idea (for now, I guess, haha). REF is such a great plugin - I've had no errors in a while with new scenes. Thanks again for all your hard work!