Assuming at least one of the axles is driven by an electric motor, you can lock them in software. That's also what you'd need to do for rock crawling - you don't just want to avoid losing power to a lifted wheel, you want all wheels to rotate with the same steady velocity regardless of conditions so that all wheels remain in static friction (zero slip, which is not possible with e.g. brake-driven soft locking).

An electric vehicle with a motor per wheel can do this. Your vehicle would need lockers on front and rear diff, and appropriate software to soft-lock front and rear.