At one point (my original training & first career was as a cook) I got interested in what was used before modern culinary parchment paper, which I'm sure you know is pretty new and totally unrelated to what was called parchment historically.

Seems like the answer was a huge array of per-application techniques though, with wax paper being the most similar to parchment but obviously not appropriate for a lot of things. Sometimes a layer of beeswax was used directly, melted into the pan and cooled; a lot of things that will absorb oil and stick don't do that with wax. Though others will stick to the wax and then it's a mess. Like I said per-application.

I believe cheesecake is a pretty new food but there are some similar/related dishes in slavic & french food traditions. For crustless custards the french moves have mostly been to just cut it out of the pan and then clean up the sides in a separate step. Either smoothing with a hot knife, or by applying some other intentional rough texture like crosshatching, or coating it in ganache or piped pastry cream or something to hide the damage.

For the slavic moulded easter cheeses (pashka) they lay wet cheesecloth into the pan first and the final food just has that texture on it along with the moulded pattern. Though those aren't baked, but some modern cheesecakes aren't baked either. I have also known pastry cooks that just ran the crust all the way up the side of the pan. Not quite the standard move and it changes the crust:filling ratio by quite a bit but it's not freakish either.

Sorry if this is an unwanted info dump, it's an interesting subject that I've also spent some time on in various ways over the years.