Question regarding finding block
Now when a miner finds a block, does the block finder get an extra bonus for finding block?
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No, since all that does is increase variance for everyone.
The bonus has to come from somewhere ... it comes from everyone who didn't find that block.
What it would mean is that in general everyone gets paid less per block, to cover the finder bonus.
Since you have no control over finding blocks, it does nothing but randomly give the block finder, part of everyone else's mining reward.