@MrWho I think you might want to consider setting some criteria for the guaranteed shares else there might be a problem of spamming the pool with numerous addresses just to earn the 2 burst which becomes something reasonable over time. Maybe like setting a mininum mining capacity before one earns the guaranteed share.
I happen to create 10 new addresses with 1 gig of plots each to test how the spamming might occur and surprisingly, the spam plots earned more cumulatively than my 250 gig plot file and each spam address brought in an average of about 15 burst every 2 days totalling about 500 bursts mining an average of 3 hours or less a day for more than a week. Imagine there was about 100 spam accounts with 1 gig plots it could easily amass up to 7k-10k bursts a week doing practically nothing. I think this might also be responsible for the recent increase of the total pool miner in just 2 days putting more load on the pool servers.
The bursts paid to my spam addresses would be refunded to the pool address and the spam accounts deactivated from mining.