I am planning to just do it and see if it catches fire actually, but certainly hoping someone can shed technical light whether these switching power supplies can manage a higher frequency.
If it was 'just' a switching supply with NO power-factor compensation then yes 80Hz would work fine but it will not increase power per-se and will certainly not increase power out of the PSU.
That said, for the past oh, 10 years or so in the interest of increasing PSU efficiency and even more importantly greatly reduce/virtually eliminate the high power-factor that any capacitor input load presents to the power line all PSU's that can deliver more than 500W are required to use PFC (Power Factor Control) circuits and those are very sensitive to frequency. Go outside the 50-60Hz design parameters and yes, the Majik Smoke will escape...