OK update.

I put on a set of 9mm (double) CR bolts with a single ring on the inside of the crank spider.
I then put 242 (blue) loctite on the bolts and nuts, and then cranked them down with a 5mm hex and a CR nut tool.

approx 20 miles into a ride, I get the dreaded loose CR bolt creak.
all bolts had come loose, at least partially.

I think i will put on my BMX crankset and see how that works out.

so my question is, how do people keep their setups tight and bombproof?
what a PITA