Really unsafe
Tonight's UA 664 had a actually no gate lice at all.
But the one and only disabled pre-boarder had the emergency exit beep. The GA asked the typical questions and let him pass. But this guy really had all rights to preboard, he was fragile and very very slow. But she still let him sit in the emergency exit row. When I boarded next as GS I asked her about it and voiced my concern. She ignored it.