UASF is a wonderful tool in today's bitcoin political environment, I have no reason to believe it is unsafe and will not work as specified.
I prefer the Flag Day approach, precisely because of the toxic political environment you're referring to (or at least I'm calling it toxic). But it's arguably UASF in a different guise, although "user activated" is a little of a misnomer for Flag Day activation.
Any sane UASF will use a flag-day for the activation.