Many likely already do exactly that. It's similar to computer power supplies, which can often (at least if they don't claim active PFC) just take DC at 320 V if set to 230 V AC, because the current handling on the bridge rectifier is specified for 115/120V, which results in a their current rating only being half-used at 230 V.
Which reminds me to check a modern server power supply for whether it could just be switched over to a battery bank at a suitable voltage on power loss. Most load should be easy to shed in a couple seconds by triggering suspend-to-RAM, and UPS are wastefully expensive if they only exist to tank full load for a moment and standby/idle for long enough to handle manual filling and starting of a generator.
