If I live 30 minutes from LTN start of security, from there I know it takes 10 minutes to get to the gate, and I need to be at the gate at T-20, I leave home at T-60.

Because of potential delays in traffic, late taxi etc, I leave 60 minutes of padding, at T-120.

Now, thanks to this new move (is it just Easyjet, or all LTN flights?) I need to be at the start of security by T-55, but with no change in the padding needed for traffic, I now have to leave home at T-145, 25 minutes earlier than before. My journey now takes 25 minutes longer. For a day trip (assuming conformance catches on at the other end), that's an extra hour a day away from my family.

If you're at the gate at the time it states on your boarding card, you get on the plane. If you're still in security (having spent 30 minutes there), you get offloaded. I don't see how conformance makes a difference to this