Not too sure about the vacuum effects, I suspect the electrolytics wouldn’t last long as they are built to handle a certain pressure then pop to vent in a controlled manner in the event of failure. The positive pressure under operation is also likely to inject liquid refrigerant into the components and into layers of the PCB and such, that cant be good for any of it, that would definitely kill capacitors by displacing and or dissolving the electrolyte fluid.
As for the longer term, I know that pretty much all of the phase change fluids you would likely use act as pretty strong solvents in their liquid states, so I doubt the hardware would survive terribly long.
There are immersion cooled computer systems using an inert liquid like Perfluoro(2-methyl-3-pentanone) but that is a different process to phase change refrigeration.