Searched and couldn't find this as already reported. No option to play the "Estate/Clerk" from hand at the start of the turn. Seems to me the Start of the turn is a part of the turn, so it should be playable.
Since fall 2019, Inheritance has changed. It no longer makes Estates gain the abilities of the other card. Now it just gives them the ability to play the set aside card:
QuoteOnce per game: Set aside a non-Command Action card from the Supply costing up to $4. Move your Estate token to it. (During your turns, Estates are also Command Actions with "Play the card with your Estate token, leaving it there.")
(emphasis mine)
If you have inherited Clerk, that means your Estates can play the set aside Clerk. But nothing gives the Estates the ability to be played "for free" at start of turn.