I don't see any problem, I just believe that unless you shoot and clean you don't really brake the barrel in because the copper fouling prevents the bullet from breaking it in as fast, and the brake in can be uneven and prevent the barrel from reaching it's potential.
I have taken barrels with hundreds of rounds through them and when you cleaned them, they fouled all over again for the same reason. then when I decided to do a normal break in, they stopped fouling as quick and shot better groups.
I have also started out using a chronograph and saw very little improvements in velocity if I didn't clean every round in the beginning and load development did not go well and took many load to find the "one".
Not to long ago I decided to chronograph a brand new premium hand lapped barrel
from the first shot fired in it until I saw a change in it using the shoot and clean procedure for break in. I was surprised with what I saw in the test.
Here are the results =
https://www.longrangehunting.com/threads/new-barrel-break-in-and-cleaning-methods.160450/page-2 Post # 20
I had known for many years that a good break in was important and had many benefits but the test proved it at least to me. judge it for your selves and decide if it makes a deference.
J E CUSTOM