Can GMB hurt rankings?

Every site we build, we heavily optimize our GMB page.

Only one site doesn't have a GMB, we are looking to rank nationally and worried about being locked to a specific region.

Has anyone experienced negative effects from adding a GMB?

My guess is that it can only add and not have a negative impact ( im no expert so sorry if i am wrong ). You could always look at getting lots of GMB listings dotted around and optimise each one?

Best of luck though.

I use GMB for my affiliate sites as well to establish that i run a real business of reviewing products. I usually have no issues in ranking for national terms