New PB for Endless Boss - made possible by SuperMagnetism + SuperHoming + Ghost (unfortunately no Dividing). Perks were good enough to go to 2,000 but I’d already spent over 24 hours on the run (with breaks of course!) and if I’d left it overnight again I’d miss out on Thermal Thursday so I suicided after 1700.
There’s an interesting moment where I take a hit in 1702 but don’t take any damage 
Here’s the build:
And here’s the recording from 1600 onwards:
I reached level 25 (max) at around room 521 because I was able to get Fast Learner early. I’d been informed that even after 25 there was slow progress and in this run was able to see it myself - but of course it’s so slow that it would take several thousands of rooms to get to 26.
I was able to get the following perks from Hidden Treasures :
- Big Attack Up x2
- Improved Poison
- Tank
- Triple Jump
- Safety Bubble
- Big Attack Speed Up x2
- 3rd Spread Shot
- Power Tripper
- Balloon
- Improved Fire
- Gunheart