NorthernSRX had it right. Both engines are the "LGY - 3.0L TWIN TURBO V6, SIDI WITH AUTOMATIC STOP/START." The CT5 only comes with 3 engines now. 2.0, 3.0 and 6.2, with different tunes across the range. The CT6 did also come with the same LGY as the CT5, and it was rated for 404hp.
Opinion: Trifecta has made a couple of claims but I haven't seen much evidence yet. I know they have the Procharged Corvette now, but Prochager straight up says their tuning solution is custom. Whether it's a more advanced version of a piggy back than the JB4 or a stand alone solution, who knows. Trifecta has made claims for the CT4 BW and CT5 V, too, with little other information given. I guess we'll see what comes of it.
Opinion 2.0: I have the JB4. It's the first piggy back system I've ever had on a car...everything else has been proper tunes from various companies. The JB4 certainly isn't my preferred method, but it's better than nothing. It does say it's in beta, but there's a group of us who have it figured out about 95%. I say 95% in that we for sure aren't getting as much power as we could if we had a proper tune, or possibly even more development work done on the JB4 specifically for our cars, but we're all at a spot where it runs with considerably more power than stock without any major hiccups.