Does this sound dumb

So i guess I'm lazy and I like acronyms so I started to call the extreme modes

GEX, TEX, iREX,

Now I wonder if people think I'm stupid haha

Of course not.

Nope. Toss them around in parentheses and they might catch on.

I dont love it ;P

They are too long
It should be GX, TX and IX

It's significantly dumber that you're even asking this question, so I wouldn't worry about your acronyms.

Better than people calling them "EM" which I can't help but turn into "Easy Mode" every time I read it.

People will be asking you what the acronyms are and you'll have to type out the full name.
In reality I think using confusing acronyms like those will be more work.