How to counter black’s early e5 on the Stonewall?


Why not play f4 instead of e3? then play e3 later?
In order to free the white bishop, as to place him on d3 and not allow black's white bishop to control the diagonal
No reason to play f4 to prevent e5; e5 simply loses a pawn and you should be happy to be up material 3 moves into the game. Just keep developing pieces normally afterwards