I am curious what a bipod or rest has to do with eye-relief?
A pistol scope has 15 inches eye relief and you get a small picture
a rifle scope is 3.5-3.75 inches eye relief
these rifle cartridge bolt action pistols are mostly not held at arms length to shoot they are shot from a rest or sticks , or bi-pod from prone , a table or hood of truck because of the large muzzle brake the gun recoil is almost non existent , they also weigh a few pounds
so when shooting from a rest they can get excellent accuracy , you just have to move your face a bit closer a sock full of rice as a rear rest squeeze bag you can make tiny adjustments and then let that round go