Its kind of convoluted but the logic works. The flashpro uses the lower of the values

 

It seems sort of redundant, but you confirmed my understanding of Hondata's explanation. Back on topic, it sounds like you're right. I'd be careful about taking away any strong conclusions about power you might have gained or lost from the exhaust until the belt slip issue is resolved.

[EDIT] I'll concede I don't know much about timing maps for the S2000, but 23 degrees seems a little high for a stock compression motor. It might be a good thing that knock limit table is looking out for you.

 

Im not so sure its using the knock ignition limit values. In the datalogs, it clearly shows the timing hitting 21 or 23 depending on the calibration. Im unfamiliar with these knock tables though.

 

Stock timing on a stock s2k ecu is generally right about 30 degrees peak, however ive seen as high as 36 on my lower compression motor running a stock ecu. I attribute this to the ecu running full advance with no knock retard, and this due to the iron sleeve damping the false knock frequencies and the lower compression, allowing the ecu to run timing at the peak of the factory advance. Generally the stock motor runs about 30-33 degrees though.

Also the general rule is to pull one degree of timer per 1lb of boost, so with that in mind running 21-23 degrees of total timing at 8.5psi is right in safe range.

The comptech supercharger kits up until just a few years ago offered no timing control with their base kits and so these ran up to 7psi with the stock timing advance. In my experience and hundreds of other owners over the last decade have had much reliable long term success. So pulling any timing at all at just 8psi such as the op map shows is not something id be concerned with, and also becuase he is running water/meth. In all rights, he should have no detonation present running the stock timing advance or more, however it likely wouldn't provide any power benefit.