The TCM is inside many transmissions, bathed in fluid and very, very, very seldom do they fail. Actually, the fail even less than that so nothing to worry about. The external, underhood mounted ones fail more often, and that's still rare. Water and even worse, water with road salt dissolved in it, are what kill them if the case seal leaks and inside the trans, no water or salt (hopefully!).
BTW, the crank position sensor is only for the engine. Transmissions have separate input and output speed sensors (many times 4 or 5 of them total).
A stand alone trans controller is about the only way I can see that trans working with an LA engine since the TCM gets much of it's input data from the ECM (and even the ABS module in certain cases). I'm curious to see what they do to get it all to work. All I do know is, it's way beyond my capabilities!
A little off the topic thing. My mother's cousin (I think he is, or was, her cousin) owned a ranch in Kansas. I remember once hearing him mention he had 2 guys who work full time just maintaining the fence around the ranch,,,,,,,,,,80 miles of fence. When they'd get back to where they started weeks earlier, it was time to start back around again. Darn cattle are hard on fences it seems. It was a wooden double rail type fence. He bought a brand new Caddy every year, probably out of pocket change, lol! Almost like one of those Texas ranchers "Time to trade in the Lincoln, ashtrays are full". Sounds like he was a successful farmer as well. Not sure but I imagine he's passed away by now. It's been 45 years since then.