@Grant-Fraser, I have often wondered if our chiller unit may be too efficient. This seems like a valid issue. I had assumed that the tubes were likely borosilicate glass and should stand up to the temperature changes better without cracking.
I’m wondering if a less expensive laser tube might be associated with less expensive glass thereby increasing the failure rate, especially with overkill cooling. I’m not saying we have that, just that if we did, it would kill cheap glass faster than HQ borosilicate glass.
I have no idea what any of the tubes are actually made of, but maybe it is something worth examining when we are comparing specs.