What is the biggest age difference you’re willing to entertain for a partner?

I have had twice in life boyfriends of around 20 years older. The first one we stayed together for five years..the second one was around a year of on and off dating... I believe things can work with age gaps but... for my particular case, i think it was more of a pathological thing, sth like looking for a living father figure of some sort, amongst other things. In exchange, it was as if they needed me to alleviate their darkness and deep loneliness.
I needed that hug and safety back then, but now, looking back at it, I think it would be best to have a friend for that purpose rather than a partner.
In the first case I was overconsumed by the relationship, he "knew everything" and I felt as if there wasn't enough space for me to live and experiment with life...after few years in, i was being so controlled.
And in the second scenario...you might laugh but, his bad coughs at his 50s cause of excessive smoking was not a sexy thing...

Ok these harsh truths being said, I still think not all cases are alike and age difference relationships can work...but needs a level of maturity from both parts...