Thanks so much for linking the Sandisk program and refreshing my memory about this - I was actually using a Sandisk SD card which came with a free subscription to this exact software (RescuePRO Deluxe), but I had totally forgotten about it. Happy to say that after 5+ hours of recovering, I was able to use it to retrieve 523 images that I thought were wiped out. What a huge relief!
The fact that they included the subscription to the recovery software makes me concerned that this is a very frequent problem (SD card file integrity issues), otherwise they wouldn't be bundling the software with their SD cards. Not sure if it was a buffer-specific issue with the Fuji camera (X-T3) itself, as it seems like I was doing multi-bursts (~11 fps) in CH mode at the moment when the storage was corrupted (also noticed a few frames that were malformed too even after recovery).