Hi, I didn't see mentioned that you are using water/meth injection. This would be the next upgrade I would be doing.
12800rpm is getting to be about the max for a straight lobe blower, anymore rpm will be unlikely to produce more power because of the heat produced.
You used to be able to get a temp probe from jaycar part number xc0224 that had min max memory, I fitted one below my blower outlet to keep a check on the temps, but it doesn't look like jaycar sell them anymore.