The photon is fine with a T20 on top , I use two the 6,5 & the 4,6 I found the 6,5 with the bigger objective a big advantage , swapping between a ,22 and 22,250 .
You can get problems zeroing the ,22 unless you use the correct mounts as you run out of elevation I shimmed the rear mount with no loss of zero removing the unit and refitting ( keep the mounts on the photon and remove as a unit ) use them in the day time as well .
The 4,6 is swapped around a pcp the same , there are two for sale on the forum .
ATB