For me when it comes to full disclosure I would ask partners about their sexual orientation, whether they've used sex workers in the past and also whether they have any fetishes, and if they're into anything particularly weird.
You're asking. Asking is fine because you aren't expecting me to mind read.
As for saying you're not a mind reader and you don't know what could be a dealbreaker for partners that you might have to fully disclose.....
I think that's pretty disingenuous. We don't know what is a dealbreaker for individual people or not, but almost everyone knows what things are potential dealbreakers for some partners.
From hereon, I decree that everyone must proactively disclose prior to sex whether they've ever voted Tory, because I've met three people for whom that's a dealbreaker, so based on my entirely objective and scientific§ dataset of every person I've been to bed with, this is a common enough dealbreaker that we should all anticipate it.
I've deliberately picked something that I suspect will sound silly (I'm not sure though as a not a mindreader, and it certainly wasn't silly for the three people in question) to make a point.
I'm autistic. I was raped at 19 in part because I didn't understand that "do you want to come to see my guitar and valve amp?" was at best code for sex and at worst a ruse to get me back to his room alone and I didn't realise in anything like enough time. There's no such thing as "use your common sense" or "everyone knows..." for me. There can't be, it's inherent to autism that we lack the neurotypical ability to partialy infer what others are thinking. So you spell out what your dealbreakers are because I know what mine are but I also know that you are not me and will not think like I do.
Calling me a liar and disingenuous for taking this approach is not only offensive, it's ablist.
§ This is sarcasm.