I've given up on waiting for a reply. I'm trying to get my hands on a TL866CS MiniPro which supports the chips listed on www.autoelectric.cn/minipro/MiniProSupportList.txt and seems to be an inexpensive, 16V8-aware alternative.
Unfortunate that I didn't realise GQ4X was shy of GALs before I included a GAL in my design.