If you are talking about an E-LSA RV-12, and the inspections prescribed by Rotax (not the annual condition inspection), there is technically no certification requirement.
If you don't have any of the certification training and you file a warranty claim at some point, I suppose Rotax could possibly deny the claim (But I am not aware of that ever happening... they have a lot of engines that were purchased by homebuilders... that would be bad for business I think)
The only certification technically required for E-LSA is the Repairman - Inspector certification to allow you to sign off the annual condition inspection.
BTW, required or not, I highly recommend that anyone intending to do any maint on a 912 Rotax, at least get the Service Specialty training. It can actually save you money in un-needed repairs.