The dives Ive seen rebreathers used on were the Great Blue Hole and Terneffe Reef in Belize. If you dive, they should both be on your bucket list! And, they are both dives that taunt you with the bottom rows of the recreational dive limits. I spent 7 minutes at 145 feet, where my dive computer gave up beeping warnings at me and just sulked for the remainder of the dive. It was a great opportunity to experience nitrogen narcosis in a fairly well supervised trip.
This page here shows the dive profiles; escorted trips dive the south grotto which pushes the 110' limit just getting there. Rebreathers give you a lot more flexibility to explore, with better bottom times.
A problem using Triton here is all the water is anaerobic, there is no oxygen and thus no sea life below the thermocline, and nothing for the Triton or LikeAFish to extract. Conditions like that can happen unexpectedly anywhere on medium depth dives. Thermoclines shift and below them there is little interaction with oxygenated surface water. So Triton et al would presumably just shut down suddenly and without warning or any reserve even during shallow dives. Not good. Carrying a pony bottle would be mandatory.
Thanks for the link on other dissolved gasses. Nitrogen is available then at ~150% by volume of oxygen. Lets make some assumptions: Troton could use the same membrane for both oxygen and nitrogen; that they both extract 50% efficiency. You need 12L to get a breath of O2 but 40L to get the nitrogen. At 15 bpm we're up to 600 lpm to process. at surface pressure. At 60 foot depth thats 3 atmospheres, so 1800 liters per minute! A sump pump at 1/4 HP does about 80 lpm at no head/pressure, so 5 HP if the triton needs no pressure for the membrane, which I guess is does (reverse osmosis needs about 50psi) so we are probably close to 20HP to run it. Thats a gas-burning outboard motor, not a pair of Duracell AA's and a few CC's of motor.
You and I between us have almost assuredly done more real work on the Triton than the clown that "invented" it; a college sophomore with no engineering background except a working knowledge of Solidworks and access to a 3D printer, and a single escorted rec dive to his credit.