Electronic Stability Control can sort of mimic a limited slip differential, but I doubt it will work well for rock crawling without at least having been tuned explicitly for it.
Even limited slip differentials are not normally suited for this - the engagement of a viscous LSD is proportional to the current slippage, meaning that you only get a notable lock once the other wheels are spinning aggressively. That’s not usable when you want to go slow and steady. In rock-crawling, you want all wheels to spin at the same steady speed regardless of traction, allowing them all to remain in static friction to ensure all wheels provide all available traction regardless of conditions.
But, “or equivalent” is important - independent wheel motor setups are superior to lockers - assuming it’s tuned right - so it should be allowed.
Even limited slip differentials are not normally suited for this - the engagement of a viscous LSD is proportional to the current slippage, meaning that you only get a notable lock once the other wheels are spinning aggressively. That’s not usable when you want to go slow and steady. In rock-crawling, you want all wheels to spin at the same steady speed regardless of traction, allowing them all to remain in static friction to ensure all wheels provide all available traction regardless of conditions.
But, “or equivalent” is important - independent wheel motor setups are superior to lockers - assuming it’s tuned right - so it should be allowed.