So in the interim, I've had some unusual failures on the MBE, not hard crashes, more like gentle failures and reboots. I gave it some thought and puzzled over the lack of anything I could readily identify as an issue in the logs and thought to myself, I had one hardware failure (old MB) and replaced it with an exact replica/vintage board...what are the chances that both of them are starting to flake.
So I had time to either troubleshoot or swap hardware, but not both.
I once again swapped out the MBs. Basically the Intel Graphics MB that I had installed to replace the Nvidea MB from the SBE, was swapped into service as the MBE, while the Nvidea MB went back to its original position as the SBE. Again, thanks for the upgrade ISO pointer, I can attest to that being a very easy way to preserve your recordings and migrating from one MB to a very different one (multiple times

).
So, currently everything appears to be working normally, we will see what happens to the MBE once it gets hit with having to deal with multiple recordings while streaming a recording.
I will keep an eye on the Nvidea MB in the seldom used SBE to see what the logs show and bite the bullet and replace it down the road when it fails.
Bruce.