I don't have a ready answer for this so please bear with me…
I am starting to find that an hour spent developing a feature or – worse – making some planned changes – can then lead to two hours bringing all of the skins up to date. I accept the need to update them all and that in itself is not a problem.
The real probem is that the skins, as a collection, have totally lost their cohesion. There are bits in one that are not reflected in another or sometimes all. There are entries in a class that are missing from others. You only havew to look at the different lengths (line count) to see the problem.
The original focus was to keep 'default' as a master skin and template and to keep them all in sync, line for line. That is why there are entries like 'border: inherit' – just to keep all the files in line.
Getting back to this has a major advantage in keeping them synced in the future. I just doubt either of us want to do it! The additional probem of course, is that testing each skin is now more of an imperative than ever before.
(And, by the way – we are both guilty of this. This is not directed at either of us).