I think this how gone way past PRS now... Ironic this discipline arguably requires the least out of rifle accuracy. Especially in Canada and it's limited distances.
A few points to consider.. again, if you are happy with the level of peformance, then just file the following in interesting junk....
With ammo tuning, the vertical component of the group changes very quickly with incremental changes in powder charge ie... the left and right may be the same but the up and down will change a substantial amount. ... test in 0.1gr increments at 250yds to 300m on either side of the ideal charge weight. The effect is very pronounced and will be easy to see on target.
Obviously, you need a scale that is accurate to under 0.1gr to make ammo at each 0.1gr increment.
I have never seen a cartridge in the 308 or smaller case volume that didn't react to 0.2- 0.3gr of powder change.... many can show a change at the 0.1gr level.
No matter how stable a powder, ALL will change a bit over large swings in ambient temperature... same effect as adjusting your powder charge a tenth or two.
By doing this simple test, you will get to prove how sensitive your rig is to both temp swings and load tuning. Ideally, you would want to load in the middle of your node so you have room on either side for changes in temp. The more your powder charge varies, the closer some of your ammo will be to dropping out of your node when affected by the same temp effect.
PRS may not require the most accurate set up BUT it does reward shooters that have repeatable and reliable drop charts. If the vertical tuning of your rifle can vary due to powder charge variations AND temp changes, how stable will your dope chart be if the groups can change vertically as much as 1.5 MOA at distance?
Testing your rig under the conditions you play will determine whether any of this matters and to what extent. I have spent years field shooting on rocks and gongs long before I got into F class. The vertical ping pong that I suffered in the early days is what taught me about load tuning vs vertical... and the need for better scales.
Going high and low on a target is not only frustrating, it makes it hard to figure out the elevation dope as distances reach out. Where exactly is my group center? If I hit low at one yardage, do I dial more at another?
For my prep into the PRS game, I am going to put alot of emphasis on making my vertical tuning as stable and consistent as possible. That way I am only worrying about the left and right. And getting precise repeatable powder charges is a main part of this tuning.
1/2 MOA may be "enough" but to maintain that all the way out to 1200+yds requires tuning on par with LR BR and F class rifles.
YMMV.
Jerry