Reducing heat by venting the component or cabinet can extend tube longevity. Suggest that you visit; https://acifinity.com
for a wide selection of component/enclosure heat extraction units. I have one of their units placed directly on top of a Prima Luna EVO 400 integrated amp. It's like they are made for each other. It drops the temp around the tubes by about 12/15 degrees. Btw since these are extraction units rather blowing cool air onto the tubes there is never a risk of thermal shock damage to the hot tube.
Enjoy the music..