I found and fixed two issues:

• I had applied $(OPTIC) -> $(OPTIC)$(num) the other day when I shouldn't have - this screen was already expecting OPTIC = IM (not OPTIC = IM1 or the like).
• There were some left over references to signals with R0 in the name (apparently left over from adapting SUS_CUST_QUAD_DACKILL.adl).

I committed the fix.