Gating mechanical rewards behind IMM approval isn't a good thing.

(1) It increases administrative burden. This increases the workload of IMMs. And when IMMs fail to reward as "expected", players are unhappy.

(2) It increases envy of successful (edge-earning) players. When IMMs reward some player, other players are unhappy.

(3) It reduces predictability of a character build.

The average effect is to increase player unhappiness.

Better to say "no rewards for PKing, and everyone gets edges as if they had gained 50 PKs". Then noobs (who won't hit 50) will gain, and vets (who can hit the 100, or 200 marks) will lose slightly, but vets are going to slaughter noobs even with no edges, so it is not so bad.