Newbies take it from an "Oldie: Don't EVER stick to one provider and call her your ATF. Keep at least 4 or 5 ATF's and rotate between each of them, so if one or two of your ATF's start misbehaving or taking you for granted, you can replace 'em with new ATF's

It doesn't really matter & who is going to enforce it anyway?  Any punishment for exceeding the maximum ATF number might actually be liked by some!