I have done things to this game that morals prohibit.
Like copying a whole Skyrim main folder modded with Nexus Mod Manager from a laptop to a steam deck and "managing" this with MO2. Bonus obscenity: couldn't run the new Skyrim version instalmed on Steam Deck with the old SKSE from the laptop install, so I had to update SKSE, break compatibility with the load order, and then manualy find which of the mods to update for it to run. Do note that I have 250 mods and an historic 70+ level build on this instance.
I guess what I am saying is "you can go pretty wild with this". Start anywhere, end up anywhere, mod the shit out if it.
I would advise on following one of the "FULL OVERHAUL NOTHING UNTOUCHED" modding guide, just because why not. Most of them have some form of attention to performance that will help with your issue.
I followed lexy's : https://lexyslotd.com/
May I ask what kind of performance problem you have on what hardware ?
If you look at the IPA, the top table represents all the consonants of human languages (almost).
You are interested in the "fricative" line. It starts with a circle with a vertical line, that's a consonant made by litteraly blowing air through your lips, like when exhaling through your mouth, almost whistling but not quite.
Going right from there, pay attention only to the left sign in each block of 2. Each step represents a step backward in your mouth. The second one is recognizable, it's an "F", classic. Third one, the eye of Sauron, is a "TH". Then an "S".
Keep going backward, and the "ICH" is that ç thing.
The small x is the sound that Hawk Tua girl made (the very start of it, the hard "H"). You went to far, come back a bit in your mouth :)
...I realized that's probably the worst phonetic lesson ever. Goodbye.