I_fucking_hate_them_now
I’ve recently learned that in Linux, you can use emois in filenames. I died a little lot inside when I learned that.
On Linux file systems you can use any utf-8 character except NUL, and / is a reserved character.

So … is allowed, or all whitespace, or Zalgo text.

I mean, on the one hand, I guess why be restrictive, but on the other I feel like requiring something that looks like language somehow might be a good idea to avoid edge cases and attacks.

You can have new lines in your file names. YSAP has a good video/playlist about how to deal with these and many more.
Listing and Looping Files (again) in Bash - You Suck at Programming #003

YouTube
could you have .​.? I assume most terminals would just spell out .\x200b.?

Or use a hair space so it looks almost the same. Or … but you’ve added the right-to-left unicode character. I’m guessing there’s something that looks a lot like a period, too.

If ext4 doesn’t include restrictions terminals probably should.