Are you talking about the margin? Quite sure TM1 did not extend background fills to the margin.

You're right. It didn't, but it had much smaller margin (left gap between text view & line numbers).

TM1 (r1631)

TM2 (r9005)

I haven’t fully settled on how to handle this — for example you can also change background for a subset of a line which may be wrapped.

Well you can just add (+) these colors (unless they have no alpha, then I'd use wrap bg unless it is defined) ? But it seems TM2 does not blend colors as TM1 did, at least I found it does not respect alpha value for hidden (whitespace) characters.

Btw. Sorry for asking that once again, but is there any chance to set the line height as reported by the font (or port OakLineHeightDelta setting to TM2)? I really find TM2 line height disturbing when switching forth & back to Mail.app, Xcode & TM2. TM2 just wastes too much screen space. Anyway you can always enlarge the font or change it to different family it you prefer more spacing.

Aside of that, I am using TM2 now for daily work and it is rock solid for me.

Cheers,
-- 
Adam