The obvious thing is POI. Not a big deal.....just re zero the rifle and write down the adjustments that you had to make. Those adjustments will never change.
BUT, you also should check your "tune". You are adding and subtracting weight and also moving that weight around, just like a tuner. My 1st year on the IBS 1000 yard BR circit I ran a single 17 lb 300 WBY in both the LG and HG class. Muzzle breaks were OK in the LG class, but not in the HG class. So, off came the break for the HG class. Now it didn't take me long to figure out that there was a 1.25 MOA shift at 2:00 whenever I removed the break. Simpe fix, just dial in or out the shift whenever I removed or instaled the break.
What I didn't figure out till the end of the season is that my "tune" had also changed when I removed the break. I was having a VERY sucsessfull year, but noticed that my year long 10 shot group size with the break removed was nearly identical to the groups I was getting with the break on and shooting 5 shot groups. So the last match of the year in Iowa I shot the LG class without the break. All of a sudden my 5-7 inch five shot groups were 2.xx to 3.xx!!!
The point..check and write down the POI changes and also shoot some LR groups with and without the break to see how it shoots.
Tod