Also, taking HIM requests by the dozen
To sum up what I've already mentioned on discord, perhaps elaborating or adding stuff along the way:
1) DialogueActions integration. If memory serves, vanilla HIM stuff (like penis size and trousers) are already part of the charcode, so if they new HIM parameters (body and clothing) could just be integrated into charcode, that would be great. There is already LOAD_CHARCODE, so no need to add another trigger. Also ensure that stuff like HIDE_HIM and SHOW_BALLS still works with EMH, including pertinent triggers from Dr Zombie's More Triggers mod.
2) A selection of compatible clothing. AFAIK, shoes, pants and tops already exist, and it's not like we really need a ton of variety as for the HER model. What on the RM would be compatible with EMH out of the box? Can good resourced be adapted to the new framework? Some basic underwear would not go amiss, especially if made to work with item 3:
3) A better penis. A limp penis and balls (countoured in underwear) that can grow into an erect penis. Even if it's like only three steps, that would still beat what we have today (no penis or full penis in various sizes).
4) An equipable hand. I guess this is just an art template for art to look good when he's holding it, much like a HER-gag or HER-panties, though it would be nice for a starting package to "ship" with the basic mod. He could be holding all kinds of stuff, but personally I'm mostly interested in things already in the game, to give the impression of moving them around for various purposes, for example: butt plugs, restraints, clothing removed from her body etc.
5) Hand positions for HIM. Just like we have ARMS_BACK, ARMS_HIS_LEGS, we could have HAND_HERFACE, HAND_HERASS, HAND_PENIS. You mentioned this is more of an Animtools thing though. Right hand is already positionable if making a custom animtools position, but simpler interface would be appreciated. Full positioning of both hands, just like for her, would be the dream!
6) I'm quite satisfied already with what we have for body mods: torsos, heads, hairy etc. Quite a few HIM-mods on the RM actually, and would be a shame for the best ones to go to waste for incompatibility reasons. Have you examined the RM for existing resources that artists might be OK to use in the new framework? I can very much recommend this mod for consideration:
https://www.undertow.club/downloads/his-head-vaan-schutleberg.6188/