Finally got the Payday Framing Frame glitch to work yesterday. After countless failed attempts, and I don't even want to know how many hours (I kept screwing up the sequence after collecting all the items), I finally did it just right. I'll say, it really helps if the vault is in the bedroom. If you get a map where it's in the big open room with the piano, you might as well just restart.
Anyway, in actual game time, the 3 day process took me an hour and 18 minutes (12 minutes day 1, 6 minutes day 2, 60 minutes day 3). Once I had Day 3 glitched, i could have stayed in it glitching XP as long as I felt like. But an hour seemed reasonable...and I racked up a little over 10,000,000 XP. That took me from a level 67 to a level 90 and earned me 29 skill points, haha. I did it on normal difficulty though since I was solo'ing.
It would obviously take much less time with more people. There's a lot of schlepping items in this mission, paintings on day 1, paintings and money bags on day 2, tech devices, cocaine, and gold on day 3. More people means more chances to get caught, but if you're careful, the time could probably be cut in half.
On normal, you can kill up to 4 guards without triggering the alarm. It's probably smart to save at least one just in case you get surprised by a guard...but it's also good to just have less guards patrolling the house because there are a lot of cameras too (I couldn't ever find the camera room).
So, yeah...if we want to attempt this sometime, I now have the gameplan. It's weird, I know this kind of stuff is gamebreaking, but there's something about doing it in a "heist game" that makes it feel right, lol. Same as when we used to ECM rush Shadow Raid. Yeah, I know you're not supposed to, but this is a game about being criminals, stealing gold, and shooting cops. Gaming the system should be a badge of honor.