-snip-
I actually used that once like three years ago. As far as I can remember, it wasn't complicated. But what's the difference in terms of security?
You wont be able to use that in the use-case described in the OP.
You can't post the encrypted messages before the "
reveal date" because the recipients will be able to decrypt it right away.
Your first option, Bitcoin signed message will work since you can immediately post the valid signature for the message that isn't revealed yet.