Perhaps controversial, but I don't think these are the best choice for a DMR
Fundamentally the further and more accurately you want to shoot the less variation you want in power levels, both shot for shot and week to week. Spring (sniper) and HPA / AEG (DMR) lend themselves too this but gas does not.
With gas every time you pull the trigger the gas as expands from the mag and down the barrel / into the blowback unit, that expansion has the effect of cooling the mag, which reduces the pressure available for the next shot a little bit until the mag heats back up again, and the expansion / cooling effect is cumulative. The more you shoot the colder the mag gets, and the longer it takes to get back to the starting pressure. It's well known physics
The bigger the mag the more mass there is to hold onto the heat, so the slower the effect comes on (but the longer it takes to warm back up after shooting) I have the long mags for mine and see a 10-20fps variation in rapid semi auto from the first shot to the last over 10-15 rounds at about 2 rounds a second. Extrapolating that too a DMR that's shooting half as quickly and you're still seeing a larger variation than any AEG, let alone a well tuned one like a DMR
Gas guns also behave differently throughout the year, needing different mixtures of gases in summer vs winter to even work, and will perform differently from morning to afternoon on a gameday as the ambient temperature changes. Today started around 8' and ended around 18', in the morning my GBBR was a bit anemic (290-300fps at the morning chrono) by the afternoon on the same gas it was a nail driver.
Gases aside the hop unit on these also has a bit of slop in it as it's a fairly cheap component so isn't as consistent as it could be.
None of this is as dramatic as I've probably made it sound, but a good DMR all about consistency & I'm trying to explain that this doesn't have it to the same level as a HPA / AEG based DMR. Fixable perhaps, especially if you go HPA instead of gas, but this adds significantly too the overall platform cost (easily x2 overall if you don't have any HPA stuff, or + £100ish if you already have the tank, reg and hose), and I suspect a lot more trial and error & tuning than an AEG based DMR would need to achieve the same performance
As an indoor CQB gun VMP2's and gas guns in general are great (it's what I have mine for) as a mid field rifle outside they can hold their own in the right hands (obvs AEG's and HPA rifles have a lot more ammo on tap! - I was using mine for this today)... but as a DMR... you'll spending the same or more £££ and time to get something that just doesn't perform as well as an AEG based DMR.
Again, my 2p and my experience of owning both;
My DMR's AEG based & fag packet maths cost me about £500ish to build with a couple of mags. Achieves 440fps +/- 3fps and will consistently hit a man size target at about 65m, probably further. It has a precocking gearbox (perun mosfet) and a highspeed brushless motor so has the same trigger response and followup shot speed as my VMP2. Lighter too...
My CQB VMP2 + 5 Mags & all the mods cost about the same but has at best 2/3rds the predictable effective range when tuned too the same power level. I largely put this down to the power being less consistent and the hop being a bit sloppy. With a longer barrel it might be a bit more accurate a bit further out, but it's never going to be able to match the AEG.