What about c4 instead of e4? Some players might try that.
Interesting way to play against the london system.

Hmm looking at it briefly I can only see Bg7 e4 d6 Be2 Nf6 going into a kings Indian position a tempo down which doesn’t seem ideal so I’ll look at it later

Hmm looking at it briefly I can only see Bg7 e4 d6 Be2 Nf6 going into a kings Indian position a tempo down which doesn’t seem ideal so I’ll look at it later
C4 instead of e4

in the main line? I consider something like Bg7, move the knight, probably taking something, then play f5. alternatively, black could try to win the white pawn on e6, then open up with e5/f5, even as a pawn sacrifice.
I remember being bored for five hours, looking at 3...h6, but dropped it. today I noticed 2...g6, and I thought it was more promising. Tell me what you guys think! If there are any variations you think are challenging, and I didn't cover, etc.