Oh wow, I read somewhere that the long cold rest actually lets the yeast build up flavor compounds!

Did you ever try soaking it with hot water and a little dish soap before you scrape? I used to just muscle through old mastic with a scraper and a hammer, figured heat and elbow grease were the only real answers, but a guy on a crew showed me that a pump sprayer full of very hot water left to sit for 20 minutes softens that old glue way more than you'd expect. The catch is you have to work in small sections or it dries back up on you, so it's slow going either way. I still bill the extra time, because nobody ever warns you and it is not your fault the last guy glued carpet straight to the slab.

Ever notice how the people with the longest answers go totally blank when you ask them something simple? I see it at work all the time, someone will have a whole plan worked out in their head but the second you ask about one detail they never thought about, you can watch the gears lock up. Happens with politics, diets, crypto, all of it. The long answers are usually just a wall, and one honest question is the door.