Tool-assisted speedrunning (TAS) is a subcategory of speedrunning that uses emulation software or additional tools to create a precisely controlled sequence of ... History · Methodology · Community · Cheating
In this situation I would say RTA is the better option. If the IGT reverts back when you fail a checkpoint the run can essentially become a multi-segment run.
RTA timing means that once you start timing, you don't stop until the run is completed or you reset. You could do an RTA run with no timer and frame count ...