I've tried this already. What i did was a forced lag. Then i let the other player with me destroy the block. He destroyed it but it didn't destroy on my screen. Hopefully we're clear so far. I lagged, he destroyed, undestroyed on my screen. Well from there I used forest to Client/Server Synchronize. Didn't work. Block was still there for me and didn't come back for him.

But...

Just to be idiots i let him lag himself. I destroyed the block. The block was not destroyed on his screen. And so I used Forest to client/server synchronize and sure enough the block disappeared on his screen.

Judging from this I'll say a block regen is probably possible. It probably involves a 1 byte value switching from 0 to 1 to destroy the block, then back to 0 to recover the block. I'm not honestly sure as I have never been interested in something like this and therefore would have no use to recover blocks although if a program comes out that's able to do that i would gladly download it and find a good use for it.

Who knows? Maybe a trigger zone destruct scenery block (0,1) and trigger crate destruct scenery block type thing will come out after we unlock the secrets of recovering destroyed blocks! It could happen!