Thanks for PE and mtjade2007.

I think I would do more experiment using testing slide, especially look for the the quick dump and check the last one ok in terms of drain.

Expert Drum might be different as it got water jacket inside the drum, as well as the 8x10 film is really next to the wall unlike 120 roll. But 8x10 chrome is hard to come by and expensive. Have to think about this.

For ATL1500, I guess I can programme pre-rinse / final-rinse step to do the minimum 10 sec pre-soak and no doubt can check how well it drill once the process stop. (If not, I can drill it between this special programme before start the real one). Not sure this moment but would test.

Very good thread.