What's your opinion of the Microsoft Ignite 2022 demo by Mark Russinovich of their next-gen immersion-cooled setup for Azure compute nodes? Link: https://youtu.be/PO5ijv6WDv0?t=370
Not good. As you can see, even the upper side connections are submerged, and plugs still look like standard components. Nothing to say of the backplane connectors on the lower side and RAM and CPU connections. They seem to just have taken a blade enclosure and flipped it backside up. So yes, it looks expensive, maybe impressive for some audience, but totally impractical even though they claim it to be a custom design.
Your main concern seems to be with ongoing maintenance, but my understanding is that the "hyperscalers" like Azure don't do maintenance. They assemble everything once and then let failed components remain in-place and powered off.
Google championed this over a decade ago. They figured that the cost of staff, spare parts, diagnostics, etc... outweighed the cost of the hardware. If you factor in the complexity of liquid cooling, it might not make sense to repair hardware even a single compute node costs north of $20K.
