Given these differences between our engines and the Demon... "A larger 2.7-liter supercharger, Demon-specific crankshaft, camshaft, valvetrain, connecting rods, and pistons all upgrade the engine over the regular Hellcat. Dual fuel pumps"... you can bet there are a number of supporting mods (including tuning) needed to take full advantage of the bigger blower.
The bigger blower, while more efficient in the higher rev-ranges, also takes more HP per revolution. At a given psi, it will provide lower ambient air temps than the smaller blower, and it also has the capability of flowing more air into an engine with more displacement, or one that is turning more rpms. I do not know what the engine redline is of the Demon-specific engine, but given it has a different cam and valvetrain, my guess is it spins higher than the Hellcat motor we have in our THs. This would most likely be the reason for the larger supercharger in the first place.
IMHumbleO, unless you're going to "go into the motor" of your TH, and at least add a cam that can take advantage of the bigger huffer, there is no reason to do this compared to a Demonized or Livernois 925+hp setup. The larger displacement supercharger only is a _real_ benefit if you utilize its potential. At relatively sane boost levels, the difference in performance will be marginal, at best.