Turns out the issue wasn’t Unraid or the HBAs directly... it was CSM being disabled in my motherboard BIOS. (Doh!)
After enabling CSM, Unraid recognized all my drives connected to the LSI 9207-8i cards. The “problem getting id” errors disappeared, and the array started up with no issues.
I've attached the diagnostics file I was looking over while the issue was still occurring. Strange that this is a change in behavior between Unraid 6 < - > Unraid 7, but happy to have it figured out. My motherboard doesn't let me use iGPU wish CSM enabled, so that's something else I'll have to figure out.
diagnostics-20250420-1333.zip