When I download a drum kit from op1.fun they work 90% of the time. However, some kits simply crash my OG-1 when I even attempt to transfer them over.
This morning I found a possible workaround/fix:
I took one kit that was causing crashes and dropped it into the drum utility: drum utility - teenage engineering
To my surprise, there was a silent 2-second sample at the end of the kit that made the kit appear to be longer than 12s. I removed the silent sample, exported the kit, and had no issue transferring it to my OP-1.
I hope this helps someone else in the same situation!