Blackwood hasn't changed much layout-wise, of course.
But what has changed is the track geometry, it's become more bumpy, camber in certain corners has been changed. Kerbs have been made more "risen" and bumpy, and the introduction of the high sausage kerbs (don't touch those
These changes make taking the turn 2 chicane more harder as you need a perfect, slide-free line to maximise your time gain down the back straight. Time is lost and won there. Other than that, nothing else really.
@OP You're improving, so keep diggin' and you may dip into the 34s soon. Once you do that you can call yourself target achieved, as you're probably on par with your old-self.
Mikus (Mikke) is hell quick. If you're within even 1 second of his WR lap you're quick.
Goodluck buddy!
(p.s a 0.6 difference between the WR of old BL and new BL doesn't sound like much, but in slow GTi cars, it's a big difference.)