The Blue Nova 8Ah LiFePO4 Lead Acid replacement battery according to their spec sheet has the following Discharge Current ratings.1.44 A continuous and 7.2 A burst (30 seconds). This battery will not work well in your UPS if drawing more than 93W for 30 seconds during grid failure.
Read this article by ESI Africa. They are mentioning a new "SANS 10142-1-2, The wiring of premises - Part 1-2: Additional special requirements for low voltage small scale embedded generator installations connected in parallel to the normal electrical supply" standard.