I've had my Noble on a board for a year of gigs. I usually put it on the floor at gigs, rehearsals and sessions, with no issues at all. It's a pretty sturdy box and the tubes are quite protected and firmly seated with top springs to keep them in place. Many other Noble users here on TB do the same and I have never heard anyone say it was a problem.
The only precaution that I have seen suggested, and which I have done myself, is to use a heavy zip tie to really attach the Noble to the board rather than just velcro (even industrial strength velcro). I live in a climate where summer temps can push 105 at times and I have had high end velcro start to melt before.
here's mine on a Pedaltrain Metro 20 ... FWIW, this could easily fit on a smaller board too.
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