[xbkingx]

Except that fails if the browser is installed while something else CPU intensive is running, an update is installing, an antimalware process is doing its initial analysis, or the device is in battery saver mode.

As an alternative, you could do a survey at install time - check if a battery is present, get power profiles, run your benchmark js stuff, check CPU, RAM, disk type (HDD/SSD) - then download profiles for that/those configuration(s). Then put a 'sensitivity' slider in the advanced options to allow power users to tweak/turn off the limit.

No need to send me code. Cash will do fine.