I had a catastrophic failure of a spool…
The cardboard on one side de-laminated, so I thought, no problem, I’ll rip the rest off and use one of the Bambu spools… except the cardboard core was smaller, and I couldn’t get it to fit. As it was trying, i accidentally let go of the side and the entire spool went SPRONG all over my office. 
I’ve spent the last 3 days re-winding small bits onto other empy spools… winding by hand slowly, until I get to a major tangle, then cutting it so I could use the new loose end to free the tangle. This has left me with multiple spools with under 100g each.
So, emergency printing time…! I have a collection of vase-mode Christmas trees, and I wondered if AMS auto-refill could handle switching spools on a vase-mode.
IT TOTALLY CAN!
Just one small blemish/zit to indicate where it swapped rolls.
So now I have a plan… print all my Christmas ornaments ASAP… before the re-winding causes stress on the PLA and it shatters. I need to find my old Ender 3 “filament cleaner”, because I’m sure when I was untangling on the floor I got a tonne of cat hair onto it. 
I love this printer! Going to be able to salvage this accident, with minimal losses.
(edit) after a (long) weekend of printing, and re-spooling, I’m left with a grand total of … 76g of waste. Some of that was prints that finishged just after the scrap of filamnet was done from the AMS, so it gets in a weird limbo situation, where the head knows there’s filament, but the AMS says “run-out”… so I had to pull them back twice. One other failed print due to a jam… a bad kink on the scrap managed to wedge into the feeder and couldn’t feed… but didn’t fail in a way that triggered any sensors (reminded me of Ender 3 days, printing nothing in the air). The rest was just poop from so many swaps. I printed over 2 dozen green trees for my wife’s office… and can now bask in the glow of successful recovery.
Biggest lesson learned… don’t panic. As soon as I realized the Bambu spool-holder wouldn’t fit, I should’ve secured the filament and come up with a better solution.