12.3.2. says anyone using a trainer on the exclusion list will not be eligible.
12.4. is, I presume, the exclusion list although it’s called Excluded Equipment (not a lawyer but I would have thought using consistent terminology would be a good idea).
So that means anyone using a wheel-on trainer is not eligible to compete.
EDIT: On re-reading it this morning it does seem ambiguous. It should perhaps be reworded to something like “…those using a trainer or power meter that appears on the excluded equipment list in section 12.4. to report power are not eligible to compete…”
I want to know the same as Mike. What races will these rules actually apply to? The SRAM Send It series? I presume the rules applies to stuff like the national eracing championships.