You can overdrive most leds with 2x current pretty safely. I run my 219B’s at 3 amps and they survive easily on a DTP board. Your current will mostly be limited by your battery, so it really depends which 10440 battery you use.
I would not recommend on/off on fet drivers for small AAA flashlights as they will overheat. You might want to ask mtnelectronics to make you a custom firmware so it does not overheat.