For racing on dirt, the ability to run lower pressure is more important than the tire itself, especially since you’re size-limited by your frame. With a tubed clincher, you’ll have to run >110psi so as not to pinch flat.
Not true, especially if one runs latex tubes, and depending on the size of the tire. For the 2013 BWR I described above, I ran both front and rear tires @ 80-85 psi with no issues. That was good enough for even stuff like this:
In any case, I’ve had good luck with the 25C IRC RoadLite tubeless and I also like the idea of running sealant in that instead of inside a latex tube…so, that’s why I’ll probably go that route next year…but, pressure limitations isn’t one of the main reasons for that.
I don’t want to belabor this, but the OP can’t run 27mm tires, and that’s going to make a difference in what he can get away with pressure-wise. I tried latex tubed 23c clinchers some years ago for Boulder-Roubaix, and pinched at 110psi. I weigh around 172 (more than you), but the bigger issue was that it’s a pack race, and there came a lap where we hit the dirt at ~35mph and I was at the back and could not pick my own line. I should have ridden different wheels/tires for that race, but I didn’t happen to own any at the time.
I have not ridden BWR, but I do know that Battenkill is a pack race where packs of riders hit the dirt sections at high speed. BWR, in contrast, is much longer (twice as long?), with much more climbing, in a different format. In other words, you can back off the speed as required in order to preserve your equipment, and “make up” for it by picking better lines and/or climbing faster.
I absolutely believe you got away with 85psi, my point is that there are some differences in the events, and the OP can’t run the setup you ran because of clearance issues. As long as he’s buying tires anyway, tubeless + sealant is a cheaper, more robust solution than latex tubes (which are more resistant, but not immune to pinching).