Flashlight IC with various modes - what IC is that, and how to disable it?
The IC is an ASIC with built-in power transistor. You can do nothing with it, but bypass it.
Here is a similar part:

That one has 3 functions plus off (100%, 25% and flash), as clearly described in the datasheet. It also reverts into a low power mode to save the LEDs when the temperature is too high, and is protected against reverse battery.
Those resistors are 0.5 ohms, not 500 ohms, by the way.
Presumably if you can measure the forward voltage at 100% power you can replace the chip with a resistor. It's possible they've got an amazing n-channel FET in there with negligible Rds(on), as your 'just short it out' comment suggests, but I would not count on it.