First WELCOME

I have MG2, had it for a while, I also have Fishman's Triple Play, and everything below applies to it as well (they are very similar in how they function at least as it applies to this discussion anyway).

You are correct: to use MG2 as your MIDI INPUT to RealBand (or ANY DAW) for recording MIDI you need something like Loopmidi, or Loopbe1, MIDIOx, etc. (all free) to route MG2's MIDI output (your guitars notes now changed to MIDI notes) into RealBand (Sonar, FL12, Cubase, Reaper,…).

As you’ve already discovered, in MG2 you setup its MIDI OUTPUT to that 3rd party MIDI interconnects INPUT (i.e., loopmidi, loopbe1, MIDIOX) then from within RB (Sonar, Mixcraft, Reaper) you select that MIDI interconnects OUTPUT (again loopmidi, Loopbe1, MIDIOX) as RB's (or other DAW) MIDI INPUT.

Now, assuming you want to hear some musical sound as you play (and record), then from inside RB (or other DAW) you pick the VSTi that you want to HEAR, and/or record, (e.g., VSTi’s like Coyote, Addictive Drums, SampleTank, Kontakt, Sforzando, GPO5, etc.).

But as far using MG2 as a “VST” inside RealBand (or ANY DAW)- not sure why you would even want to. MG2 essentially has no NATIVE audio FX any more than it does synth (sound) generators. In that sense, “MG2 brings nothing to the table” expect the ability to turn guitar audio into MIDI (notes). If you are thinking you may want/need to do MG2 configuration changes during your DAW session, well it's already open as its own application within its own window. That's why you need that 3rd party MIDI router to connect the MG2 to DAW.

When used with a DAW to record MIDI guitar performances, MG2 is used no differently than if it were an external MIDI keyboard/controller, wind controller, MIDI drum pad/set, or 13-pin GK2/3 MIDI guitar.

If you want to RECORD the AUDIO generated by MG2 when it is set up with your favorite VSTi's and VST's that's a different discussion.

Have Fun with MG2 and RB and Good Luck!
Larry

Win10Pro,i9,64GB,2TBSSD+20TBHDDs,1080TI,BIAB'24,Scarlett18i8,Montage7,Fusion 8HD,QS8,Integra7,XV5080,QSR,SC-8850,SPLAT,FL21&others,Komp.14,IK suite&others, just a guitar player-AXE FX III &FM9T, FishmanTP, MIDIGuitar2, GK2/3'sw/GI20