The reason for the Thermal to be mounted Aft of where a day optic would be located, is because a day optic eye relief is quite different from a thermal eye relief.
Thermal optics, such a a Pulsar Trail, require more Aft mounting to allow
the shooters eye to be closer to the optic.
The factory mount that Pulsar sends
with the Trail allows the user to choose a variety of mount holes, even allowing the mount to be used in a
reversible position. The reversed position, along with the multiple holes, allows quite a few different mounting accommodations.
I also have the DLOC mount but have never ran it, as the factory mount has
always sufficed for my needs.
Bobro also makes a mount for the Trail as well..
I havent had any issues attaining a favorable mounting position for the
Pulsar Trail. I have had to get more creative when mounting my Patrol however, as its mount (Dloc) does not
allow as much adjustment For or Aft of chosen mount position on the guns receiver.
So when mounting a thermal such as a Patrol on a bolt gun, I found using a extended rail riser in reverse provided me with enough pic rail to get the Patrol Aft on the gun to achieve proper cheek weld.
Some guys (Wig ?)on an Ar15 type weapon, will just run the gun with the stock in collasped position, ie, shorter LOP, to offset the cheek weld mismatch. But he has more hours behind NV and Thermal than anyone I know, and he has tried everything! Lol
All you can do is get your thermal mounted, try different things. Settle on what works the best for you, then practice and get accustomed to it.