If the problem is on the QEMU side, getting relevant QEMU debug logs (-d in_asm,int which needs #define DEBUG_PCALL enabled in target-sparc/op_helper.c) would be needed. Those will be quite large and the relevant info is only near the end.
I'm not sure I'll be able to get/make available logs without potentially months worth of waiting for someone to approve the request. I'll have to see if I can find some 02/04 ISOs and do it on my personal laptop.
-Brian