1. Your optic means little since you wont sight through an optic, you will use an IR laser. Yes, I know its technically possible for a red dot, but it sucks so bad, you will not do it. You will only use it for white light.
2. If you will start with a PVS14 you will likely keep it if you go duals or at least run it for a long, long time before trading it in to help pay for duals. Getting the best mount for a PVS14 vs getting a mount that is better for duals should be your priority. An INVG is IMO the best for a PVS14 but still works with duals, its just bulky and heavy for no reason with duals and points them mostly straight up vs flipping back more (flipping back more puts the weight in a better spot for duals). With the INVG and PVS14, the up and to side flip is the best for compactness and weight of any mount and NV combo IMO. You can keep a mount for your PVS14 and another for your duals.
3. You need to decide if you want a push button release or force to overcome. This is personal preference. Force to overcome sucks with the bendy stock J arm or a loose head mounted platform (no tight chin strap). A DDA and a propperly tight chin strap makes it way better. Push button release to flip requires a fine motor skill to find the button, but once you hit the button, its very easy to flip and its all about training to make finding it faster and smoother. If you have your chin strap under your chin for comfort with a stock J arm, the push button is much nicer to use than force to overcome.
4. Some people use a button on the release button to kill power to the NV when flipping up. Some people use the stock magnet system to kill power when flipping up. This keeps your NV optic from getting flipped up in a lit room and pointed at an overhead lightsource and you forgot you had the PVS14 on, harming your tube. The down side is you have to manually turn on your PVS 14 afterward, which is a fine motor skill.
5. When you go to white light and red dot, depending on how you mount the gun with your face and optic height, you may rotate your head slightly on the stock, strong side and down, to get propper allignment. If you do, you may find you cant just stick a gun up to your face without flipping the NV out of the way completely or it crashes inti the side if your optic, even just a small red dot. Some mounts, even when up, especially if they flip stright up vs back on top of your head, allow the base of the PVS 14 to contact your optic, especially on scopes and magnifiers. Then you might have to use a fine motor skill to flip up, another fine motor skill to flip down, and then a fine motor skill to turn on again. This sucks.
6. I prefer to move my PVS14 with INVG going white light vs trying to co-align. I find that a force to overcome sweep to weak side with INVG to works best with it worn over my weak eye. It is fast and sweeping left/right keeps me from having the rear of the PVS14 from bumping my nasal bone as I bring it back down. You have to push pretty hard to get it moving and it usually smacks my nose coming down from front. It allows the PVS14 to stay on when flipped to side, so no need to reactivate if you just flip out of the way for white light then need to go dark again quickly. If I flip up, it is to stow up and and the magnet cuts it off. That means I wont need it again suddenly, so no hig deal to have to turn on after flipping down. But its slower for transition to have to turn back on. For those reasons, I much prefer the INVG with a PVS14. If yiu just hunt, going back and forth to white light quickly is not really a necessity.
7. For the DDA. It originally had no horizontal correction. Both the left and right eye were fixed. The newer units, the ones now made for many years, have one side with horizontal adjustment and the other side is fixed (only a few DDA with no adjustment were produced). When you use the horizontal adjustment it screws up the position if you rotate the INVG to the opposite side eye. You really have to pull the PVS14, rotate to the other DDA mount, and reinstall, but then you dont get the adjustment on your secondary side.
8. Occasionally, on long hikes, I swap the INVG arm over to the opposite eye with a loose helmet or Nightcap crooked to get it to work and get a crappy half image to walk by just to prevent headaches, but it is not ideal or very useful at all. The fixed DDA is actually fine for most people in comparison since the occular offset for most people is very similar.
I say get an INVG if you get a PVS14 if you want its features. There is nothing wrong with a G24 but its not as good on a PVS14 DDA combo for my preferences. Get the best for your actual current set up, not some small item best for a purchase you may never make for years.