Nobody is proposing doing anything with the Service Plug. The Service Plug is already weather proof, a little cool air blowing over it shouldn't hurt anything. If you are worried about something dropping down the opening then you can always put a screen over it.
Are you suggesting removing the plastic cover plate, or also the metal plate secured with 10mm bolts?
If only the former, the HV components would seem well-protected; but without the metal cover, what would prevent a spilled drink (or a water from a firefighter's hose) from infiltrating and shorting the 400V DC fuse assembly?
At the very least, some sort of splash-resistant cover would seem in order.