I never had a BATF check my C&R stuff, but it was all in order anyways. I never had them check me when I had a 01 years earlier but knew others who did get checked. My only issue was with LOE who was out of control. Looking back on it I should have let him arrest me. That lawsuit would have paid for several years of gun purchases and ammo.
Our little town has deep pockets when it comes to settling out of court I have been told. That was the apparent reason the Town Lawyer had counseled both the LEO and elected officials about exceeding his powers. They had quietly settled another issue and paid a hefty settlement claim. I think the reason the Mayor came over was to prevent another problem for the town. By the way the LEO is now retired I am told.
Unless you have a jerk LEO to deal with, then get a C&R if you want. Do be aware that you may need to keep track of purchases and potential sales taxes. Neighbor just had to pay sales taxes on pens he was making and selling. Cost him several hundred dollars in the end. There is no free lunch where governments are concerned with taxes, fees and permits.