You are welcome, Trete! Music to my ears when someone I instruct learns and grows.
No, just not
really short ones. Not with the latest BetterPenetration dll present anyway. As I said, if you use say the attached "old" dll instead of the latest, you get an older UE in the Plugins screen, NO high heel support, and the feet seem to stick to the floor plate, allowing essentially short, long, etc legs--at least until you add heels.
There's no way I know to adjust the general "floor" location coordinate wise.
Sure there is!

I'm not certain if ANY other Illusion mod artisan uses MAX(they all looooovvvvve Blender(in childish accent). But yes, the easiest approach is to import an "exported" FBX accessory file another mod artisan has created & got working in game. You can learn alot from painstaking study of your buds' success.
How you import an "exported FBX" is to use a free app (included with the Better Repacks) called SB3Utility. It's made by this total dick burger over at IllusionSoft Discord but his/her/its app is pretty nice if you don't know/want to learn Unity also. Unpacking a zipmod, you find all its guts. The CSVs that tell the game what your mod is called, what its texture's name is, etc. The thumbnail.unity3d files are there, which provide a selectable icon for your mod in Maker, and you have the mod.unity3d file(s) themselves. These are how you get your first "exported" accessory FBX.
Sorry this is a total nutshell workflow. But essentially once you have imported an exported game asset into MAX, you can replace/skinwrap your new mod to its original structure, export FBX, import FBX into a brand new zipmod(or the one you're studying too). Whatever you can do to get your stuff in the game, do it to it, Pruitt. Then you can figure out how to make it all work pretty later.