Brilliant work, my initial thoughts are that it might be significantly less work to patch/seal/address the leaks in the hull than to engineer, build, install, monitor the electronics for this. Is this not the case?
Depending on the vessel, leaks are part of the design. Seals always leak. Salt water is highly corrosive and will always "find a way." I own a smallish boat on the Gulf of Mexico with outboards (lacking the shaft seals that inboard boats have) and water STILL finds a way into the bilge. I have three pumps, one main and two redundant, just in the event one of my scupper seals goes, something/someone strikes my boat hard enough to puncture the hull below the water line, or one of my through-hull fittings (like raw water pump) develops a leak, while the boat is out in the Gulf or sitting at the marina.
Might seem like overkill where regular maintenance should be sufficient but you can never have too many redundancies to keep a boat afloat. Murphy's Law very much applies.
Something always leaks. If anything just the packings around the propeller shafts (though since this is a sailboat it may not have propeller shafts).
And there is maintenance. Even if you seal up all of the leaks, something will always degrade and start leaking. If you are away from the boat for weeks at a time, you may find your leak-free boat on the bottom of the harbor.
So yes, you could conceivably find and seal every single leak, especially if you don't have a rotating shaft that penetrates the hull, but it would not negate the need for monitoring.
https://99percentinvisible.org/episode/abandoned-ships/ just had an episode about ships where the crew is not able to get off for various reasons. One of them that I hadn't known was that if you leave before you get paid, you typically forfeit your pay.
Connection to your comment: there was a huge explosion in Beirut. There were safety issues with a ship loaded with fertilizer. The port offloaded the fertilizer and let the crew leave. One consequence was the terrible explosion. The other was that before that the ship sank. Big ships are described in the podcast as needing constant maintenance to keep them from sinking, which is one of the reasons ports are reluctant to let the crew leave.
It's a bit like saying "it's significantly less work to just fix the bugs than write unit tests".
There are always bugs (leaks) and potential for bugs (leaks), some effort in both directions is usually a better use of time (and in this case, money).
These are not exclusive propositions. You fix/patch/seal any leak you know of and can fix and set up a pump to deal with the rest. And then you monitor both to check that the pump still operates and the leak rate did not increase.
Leaks can be intermittent, and hard to resolve. I had a job driving effectively a water taxi one summer. One customer was working with one of the local boat yards to fix a recurring leak. They eventually ended up rigging up an audible alarm, probably using a float switch or something. I was given a phone number to call if I heard it ringing, or just call the yard on the radio. They eventually figured it out.
Might seem like overkill where regular maintenance should be sufficient but you can never have too many redundancies to keep a boat afloat. Murphy's Law very much applies.