Why couldn't we have after every 100 elected delegates forge a block, give 1 block to a pending delegate as a chance to prove their worth / uptime / gather stats?
That way people can vote on pending delegates based on their stats, worse case scenario - we have 1 missing block every 100 blocks. But I'm sure pending delegates would never want to miss a block.
We could also select them randomly based on their current votes as a %.