Here:
I’m hesitant to install any handy utilities unless they’re from a company that’s been around for a while (like 5 years+). I’m extra hesitant to install utilities that need to patch DLLs!
Personally I have accepted the round corners, but I must confess that back in the nineties I once themed my Windows 95 (?) install to look like macOS. 
At this point in time, Windows 11 annoys me so much, I’d find it a relief for it to be broken by something.