Apparently the mod still works fine if you don't have script extender installed. The only reason the hair extensions won't should up would be that you have another autosnap hair mod loaded, but don't have "Patches for CC Races.lsx".

Because this mod is set up to use Races.lsx (in order to make race compatibility easier for me), you will need a compatibility patch in order to use it with other mods that modify the Races.lsx. And I'm also a doofus who for some reason thought that using CF would mean compatibility with any autosnap mod, not just the ones that also use CF (which are pretty much just my other hair mods at the moment)
I like using the Compatibility Framework because compatibility can be pretty much entirely done on my end. If I add more hair extension options in the future, I just need to add entries for them to the file in the Script Extender folder... unfortunately, the framework is not psychic and will not pick up on other autosnap hairs unless the mod author also configures their mod to use CF. (Plus, Script Extender doesn't work on Mac computers)

I've also opted this mod into Padme4000's "Patches for CC Mods", and usually give her the info for hairs I plan on adding in my next update ahead of time so that there generally shouldn't be any issues with new hairs not showing up.

I'm not really actively taking requests. I've been kinda going back and forth on how strict to be about it because I am unfortunately incredibly indecisive. At the current moment, my thoughts are that if you really want to leave a suggestion, I can't stop you, but I can't promise that I will do it.
At the very least, if you do want to leave a suggestion, please keep it to just vanilla hair parts, not to make something longer or shorter or what have you. My time and especially my energy are quite limited.

If the hair it comes from had physics, then yes. I have also added physics to some hairs that don't originally have it.

Hairs that have physics are generally incompatible with other hairs that have physics.
Adding physics to a hair involves assigning a skeleton resource in the _merged entry for it, and the mesh having the appropriate vertex groups that go with that skeleton (plus weight painting, my beloathed). Pairing two hairs that have physics together can cause the skeletons to basically fight for the space they occupy, which may result in one hair pushing the other to the side, or flying up, or the both of them rotating around each other, or other weirdness.

Note that a lot of hairs in Tav's Hair Salon have skeletons assigned to them; hairs that don't have a skeleton resource assigned to them have to be conformed via Lslib or else they can get deformed in game, but if you don't want to run it through Lslib (i.e. if you're making a BUNCH of different hairs and want to save time/energy) then you can simply assign a skeleton to it in order to conform the hair. This means that even those the hairs don't actually have physics (because they don't have the specific vertex groups that go with the skeleton assigned to the hair) they will still interact with hair extensions that do use physics. There's not really anything I can do about this; Toarie would have to go back and remove the skeleton resources assigned to all those hairs AND run the meshes through Lslib. Which would be extremely tedious.

As stated in the description tab, you can find them in the "General" tab under a section labeled "Chins". If you aren't seeing them, you either 1) did not download all the requirements or 2) are using Plus UI, in which case they are in the "Body" tab (and no, I am not responsible for the changes Plus UI makes to the CC screen).

It should work with ANY race mod that uses the Celestial, Fiend, Fey, or Humanoid tags. Most custom races use the Humanoid tag, but labotor's Satyr Race uses Fey (for example).

To be compatible with other hair mods that edit the Races.lsx file (usually autosnapping hair mods), you will need the "Patches for CC Races.lsx" file from Padme4000's "Patches for CC Mods".

However, if you are using the Plus UI mod, you will not be able to select "Hide clothes" in CC. I am not Raizans, I do not control how Plus UI works.

It tells the game to fit the hair to whatever bodies you tell it to. It makes one hair model fit different size bodies. Unfortunately, this isn't perfect so they won't necessarily look good on every body.

Initially I just wanted to customize the colors and stats of some items from Basket of Equipment and I used AnteMaxx's various sample mods to figure out how to do that. Ever since moving on to mesh editing, I have relied heavily on the BG3 Wiki's Modding Resources and the help of the Down By The River discord server. I usually mention in the "Thanks" section of my mod pages specific tools and whatnot I used. I just started learning to make my own mods in October 2023 and thanks to the numerous templates and resources and helpful people and my excess of spare time I've come a long way. I highly recommend trying to get into it yourself if you want to better customize your game experience (although I don't recommend posting every mod you make online if you're easily stressed out unless you turn off all comments/forums/bug reports).

I cannot possibly know what is wrong if you don't describe the problem, provide screenshots/video, and your load order. PLEASE be as detailed as possible. I am not psychic and if you say "it's not working" without providing any further information, I will be very annoyed.