He uses Trainwrecks and AC30s for his recorded tones, so a Matchless is an interesting choice for the amp. I'm not saying it isn't the right one for the sound you want, it's just a completely different platform and voicing than the amps he uses. I'm not extremely familiar with the Matchless stuff, so I'm not really familiar with their response and how to set them up.
If it was me, I would stick with one amp that is really close to the one he uses for the tone you want and then work with it until you get what you're looking for. His main recording amp is his pre top boost AC30/4. The Dr. Z amps he plays on the road are pre-top boost AC30 based designs. His tone is a pretty good representation of that sound to me, meaning that it is definately Vox but without the high end harshness that can be present when you push a top boost. I don't hear anything unique about his amp tone really. It just sounds like an early pushed AC30 to me.
I think your best course of action would be to dial this in using good FRFR monitors or headphones using the cab block. Once you've virtually recreated his sound using the correct speaker IR, you can try to adjust it in such a way as to work with that V30 cab. Keep in mind that one of the keys to getting the Vox sound right (including Paisley) is the alnico blue or gold speaker. The way the top end compresses is magic, and a V30 just doesn't do it. If you start with the 212 Brit or 212 Gold IR (Gold would be my choice), you can get the amp settings right. Then, you can try to tweak it to work with your V30.
When I've heard what I thought was harshness, it was because I continued to tweak after my ears were fatigued and/or I had adjusted the amp or cab block in such a way that a real amp would have done the same thing.
There are just too many people who use this device and find no inherent digital harshness, so I think the more likely culprit is that you're using the wrong gear and maybe tweaking a little too hastily. I find it easiest to nail a tone by picking the closest virtual representation of what they use and forcing myself to focus on making that work instead of trying a bunch of different setups in the Axe-FX. YMMV....
Just my $.02
D