When it comes to a VAMO the "safe" issue comes down to: They use an insulator in the battery tube that surrounds the positive connector. It's nothing more than a cardboard washer that's glued into place. Some times it's "not exactly centered" and when it isn't you might have a problem with a flat top battery making a connection. Easy fix: you just take it out, apply some glue, and do a better job centering it than they did at the factory.
Honestly for a VAMO it really doesn't matter. If I had my druthers I guess I would get the button tops for a VAMO.