Nothing wrong with adding the conversion "just for the heck of it". But it's not a round with too many practical applications. Because it's extremely slow, I doubt it's able to do anything more than a 45acp already does. The velocity is the biggest shortcoming between the .50GI and rounds such as .50AE, .460Rowland, .44mag, and even 10mm...so it doesn't even really serve as an ideal hunting sidearm.
Seems like it's more of an "I've got a fitty" novelty than anything else. But heck, I'd be happy to run a few mags through one if the opportunity ever arose.