Blood Gods is essentially closed for new non-HoL gladiators already, even exiting Primus with a "normal" gladiator is very tough nowadays. The addition of the levels beyond 50 + the legendary gear made the issue with the new guys being unable to compete in the higher brackets redundant - now this is like that by design so unless Nate changes something drastically, nothing but high-tier premium slaves will be able to compete in the upper brackets. That said I don't see why the "veterans" should not gain access to some extra boost. It can come with some sort of a disadvantage, like making the respective gladiator bound to the arena for certain time after you apply the boost in question so you could not sell or retire him/her.