Come to think of it, if one agrees with the energy loss via the tow rope being the main issue, one could have a very reliable mechanical solution.

Mount the hook on a shock-absorbed sled, sled slides back enough, the release is pulled. One might have to be able to tune the compression and spring reloading based on what you're towing, but that's a very reliable solution.

Not sure how many tow-pilots would realize what's happening fast enough.