UPS for PS4 to be used only for switch overs is probably the safest bet.But UPS`s like APC , not regular ones, but bad ass large ones with online/offline configuration etc which cost around 150K to 250K can be used for longer game-plays.
Proof: Industries IT specially are running very sensitive equipment on UPS`s these days but mostly tagged along with generators backup.
For smaller ups`s , switch over usage is probably the safest.
And when I say UPS , I only mean APC ups. Not alfa , not desi and not others .