Allow "grandfathered" Nitro accounts to swap to other tiers for Nitro Boosting.

The one downside to giving grandfathered Nitro accounts a free Server Boost is that you can only use it once, and then you have to WAIT for your sub to end so you can cancel it and move on to a different plan. I don't think you thought this through, because those with Classic Nitro cannot upgrade until they cancel their sub AND wait for the billing period to pass until they can upgrade to Regular by ditching the $50 yearly to a $10 monthly, which the time they have to wait depends on when they bought it. I have to do this because I'm not willing to drop $100 just to spend a few months Nitro Boosting my favorite server. 

Please allow Grandfathered accounts to swap to any tier of Regular at least once.