1.9 has been created!
I used the requested regex (with a couple of tweaks, I think you meant "^1.9($|.|+)" ) for your 1.9 track only, give it a try and if you like it I can propagate it to the other 3 tracks.
This matches for instance:
and others. Remember the guardrail is just a minimal protection against mistakes like trying to push your 1.7 snap to the 1.8 track; in that sense, even the old regex would do.
Anyway, let me know if this fits the bill and we'll update the others.