If you're gaining advantage by changing RAM from sockets to soldered joints, it's probably time to change the system design altogether. It's better to put the DRAM on the same IC/SoC as the processor - on a dedicated die if necessary. Any additional memory requirement can be added as socket based RAM modules. They sure will be slower. But they can be treated as another memory layer, kind of like the optane memory (without persistence) or NUMA. You'd still get significant speed up because a portion of the DRAM is colocated with the CPU now.
This also adds to the core philosophy that I'm trying to push. Modularity and serviceability doesn't necessarily mean sacrificing performance, compactness or security. That's a myth that's too prevalent in the industry.