@DannyP is absolutely right to point out the difference between static and dynamic compression. I had the Panchitos cut for 9:1 and have been running high test.
During the recent (hospital) unpleasantness, I sold the lawnmower and engaged a lawn service since the grass NEVER stops growing here.
Out of curiosity, I poured 5 gallons of 87 octane left over from my mowing days into an almost empty tank. I figured I could top it off (12.5 gallon tank) with 93 if it knocked.
100 miles later with some full throttle attempts, I haven't gotten it to knock yet. The real test will be to take it up the mountain, but so far so good.
I suspect I could have cut the heads a bit more.