Honestly, for a good accurate live sound, the amp wouldn't be ideal. Especially if you use any of the acoustic models on the JTV. In ears or the Stagesource monitors would be more ideal.

Yes Stokes, I can see how opinions would vary! Here is another view

I currently use a POD XT Live and usually a 20th anniversary Squire Strat (Affinity). The guy that built it must have been in a good mood as it sounds really good. I sometimes use a Variax 500 but the intonation problems bug the heck out of me ... bridge is about 1/4" too close to the neck.  I've adjusted it as far as I can possibly do it, but I am going to have to build a new guitar or rebuild an old one that I have. I now know why people said what they did about the guitars being badly built and why Line6 brought in a proper luthier. No wonder people were buying the 300's and stuffing the electronics into Warmoth bodies. Ever notice how quickly the 300's were discontinued?

But to the topic at hand, while I can use the XT Live to plug right into the PA, I have found that to be happy with hearing myself in the monitors, I am too loud for other people on the team ... I was told once on my old praise team that I was interfering with the girls that were singing harmony. Comes from using CAGED way up the neck. Bottom line is that each guitarist is going to have their own preferred way of hearing themselves and willingness to lug equipment around. My setup allows me to walk in and out of the sound cone to increase or decrease the sound level that I am hearing. It lets me pay attention to rest of the team when needed and pay attention to what I am playing when needed.

I used to use a DI box between the pedal and the amp splitting the signal to PA and amp, But I recently picked up a tiny Marshall Lead 12 combo, 1984 vintage with a 10 inch celestion. 12 watts is plenty loud as a monitor, but this amp has a dual purpose 1/4 output on the front for headphone or line out. What I do now is use that line out to plug into the PA through the DI box. The good thing about this set up is I have the amp controls set so that I never have to adjust them. I only once brought two amps to church as I used the Marshall line out to run into my Peavy combo.

As far as layering amp sims on top of an amp, I haven't used that perspective in a long long time. Amp sims are simply a set of adjustable tonal controls with optional gain/distortion. If I like what I hear, I use it. That was probably the best way of thinking when matching Variax models with XT Live amp sims.

I have to admit that I am coming at this from the perspective of playing electric guitar. But, I have used the same setup with my acoustic. I just stand a little farther away from the amp .

I've gone both ways.  I started out with just the HD going straight to the house and now I go HD to DT25 head (I also have a DT-50 but it's too much, I'd recommend the 25) it goes to a 1x12 Blackheart cabinet with an Eminence speaker.  We have our speaker cabs in backstage enclosures and used wireless in-ears.   One thing I've come to realize and make peace with (more or less) is 1. Your in-ears will never give you a true representation of your actual guitar tone so you need to dial it in and just be confident that it will sound good.  I rarely make any adjustments once I set up my rig based on my in-ears.  2. No matter what you do or how close you get to a Holy Grail guitar tone the FOH sound guy can and probably will screw it up. 

We're a big church with a rotating band of more than 100 people so I'm always playing with different people and different people at the board.  Some board guys are guitar friendly others favor vocals or keys.  I've given up wishing for the perfect mix it just doesn't happen.  I know if a few guys are running sound to boost my volume onstage a bit right before we start and after soundcheck if I want to be heard

Back to your question though, I do find with using the DT-25 I get a lot more tube dynamics in my playing than I do with just the HD.  I have got it down now to basically 1 patch I can use for 90% of the P&W songs.  I pick light and I have a clean at the point of breakup and playing hard it really crunches and compresses just like I'd expect.  My patch is a dual amp patch with a Twin combined with an Park 75 so it is very articulate and just have a noise gate, a screamer and two delays and use an FX loop for a clean boost for solos. Check it out I'll post it here it's also on CustomTone.