Just got this in from UL:
We have released SystemInfo 5.55 that has detection for ECC status for NVIDIA GPUs.
When ECC is supported by the card (for GeForce this is 4090 and 4080 and maybe 3090 Ti?) the Graphics card data segment should include info on whether ECC was enabled or not when using this SI, so technically you could now start requiring it and checking the status from our result page. There is a performance penalty of about 4-5% for turning it on, though.
Going to ask community to try to break it before we require it for anything, but now the information is there so we can start investigating whether this is a fix for the issue.
So we are going to require ECC set to enabled from now on