There could be rewards for mining blocks. I guess you already technically do due to /levels rewards but this could be another goal to set on the server. It could be every 1 million blocks or every 2.5 million blocks or less you get a reward. It could be a "Mining Contraband" with a lootpool of rewards or regular contrabands. Or custom rewards similar to at 2.5m blocks mined you get 25m tokens, at 5m blocks you get a legendary crystal, at 25m blocks you get a Godly Crystal. Or better rewards or worst.

(set to high due to high demand)