I bet when you were assembling the press you found putting the primer slide spring on to be royal pain. Hook the open end of the spring to the press, raise the arm and use a foot long piece of fishing line through the closed loop of the spring to get on the slide pin. I don't know who thought it was a good idea to put that spring to the side of the slide facing the press instead of the outside where you could get at it without tweezers
The first time it was a PITA, but usually anything brand new is.
I had the same question - why the hell is it on the inside and not the outside? Answer is so that it is much more difficult for anything to interfere with the operation. If the spring is on the outside, it's easier for it to catch on something you have sitting right next to the press on your bench.
After having the press for a while, I can swap them out without any tools in about 5 seconds. Repetition creates familiarity, like anything else.
I would also strongly recommend to loc-tite the nut on the bottom of the primer cam rod and to occasionally ensure the jam nut on the top tat tightens it down is secure. Had one issue where the cam rod loosened up and I bent it a little bit. Now I check it about every 10k rounds to make sure it's still good and snug to hold the cam guide rod firmly in place.