That's exactly the problem with reusing a high pressure seat. The problem is you can't inspect it without removing it. And I'm not sure you'd see a developing problem anyway. But once you remove it for inspection you have now decreased it's reliability relative to just leaving it alone. That leaves no real way to improve the outcome other than replacing the seat.
Other companies with similar seats replace them annually and I do the same with Mares regs.
I am more comfortable reusing diaphragms, but care needs to be taken that they are not damaged during removal when servicing the reg.