I took a break from the extremely boring business of backing up my photography archives to go out into the late afternoon sun and shoot some high-contrast photos.
The shadows were harsh in a very satisfying way!
The defective Polaroid cartridge that I decided to salvage myself (by disassembling it, swapping out its battery for one from a recently used cartridge, and reassembling it) did work, but the vignetting was terrible, because I'd done the swapping in subdued light (rather than a darkroom) after having the new battery get caught on the metal sprint that pushes the images forward... I think I learned enough from that to be able to perform that fix in a darkroom if I ever need to again, so I can get better results.