I can tell you that when I capsized while trying to help a stranded kayaker at the Mayport Ferry dock while battling a 5 to 8 mph current I was happy to be able to freely move to the rear of the kayak and turn it to go through and not get stuck broad side to the pilings on the next fender. I was happy not to have any loose tethers, line, etc out that might get caught on a stray nail or bolt on the dock as I passed through. I did not loose contact or grip on paddle or boat.
I’ve experimented with short and long tethers between me and my paddle (to keep paddle from escaping when doing a re-entry and roll). I mostly haven’t found them to be helpful. The long tether seems to get in the way and interfere with what your body is trying to do (to get back into cockpit) and, as others have stated is an entanglement hazard. The short tether (mine was about 8" with a loop on my wrist) decreases the risk of entanglement vs the long tether but in my experience made underwater movements awkward as you’re essentially handcuffed to your paddle making everything you’re trying to do with that hand more difficult.
I’ve gotten waylaid a couple of times while camping on barrier islands, due to unexpected weather changes, and eventually had to leave under less than ideal conditions (high winds and waves). As a result, I now carry some floating line with me to attach to the boat so that just in case I did go for an unplanned swim in high winds while paddling solo, I would have a few extra seconds to grab my boat. Something like that might work for you but depending on your paddling environment, might present an additional risk of the line snagging on something.