It does effect tick speed, so this might be something we're just as happy to leave out. A little experiment into how much it effects performance would be needed as they are basically over powered sprinklers that have a stacking effect and we know how much players love sprinklers!
We do LOVE sprinklers. Is there a way to limit them to a few per chunk so players don't place to many of them?
I believe most of the Twilight Forest tree saplings are craftable if the tree of time is craftable craft the sapling grow the tree and then chop the tree down to get the clock