This might not be as ridiculous as it sounds if it were utilised for the Balearic operation. You’d be looking at an hour give or take for Palma-Ibiza and Mahon, about 1:30 for Ibiza-Alicante and Valencia, about 1:40 for Palma-Barcelona, 2 hours for Mahon-Barcelona. All much faster than the ferry and adding probably only 20 mins or so the the block times of the intra-island routes. Ibiza-Mahon is longish but this doesn’t seem to be an existing route.