I knew about that, but lets approach this differently.
How about an option that forces a package to become green, but purely cosmetically? So it still skips the files, but the packages show up as being green? Probably loads of work without a real purpose but it would solve it, I reckon.
So that if WB detects Oblivion/SI BSA or its esm/dummy plugin within a BAIN package, it will recognize this and flag the package as being green.
Did you also see http://www.gamesas.com/index.php?/topic/1180469-relz-wrye-bash-thread-63/page__view__findpost__p__17498938 - Lojack has already cracked this nut for the next release.
With the new BSA Redating on auto, and the new option in the installers options http://www.bild.me/bild.php?file=6447687Untitled.jpg my official BSAs' are showing green (well ones yellow because of a single file conflict.)
Going to the Installers tab which does a quick refresh only takes 48 seconds, only a few more than normal with my install list. The way it works now has also solved the problem whereby you would have to multi-select everything EXCEPT the original BSA installers (otherwise you would have an age to wait while it re-installed those which were previously red). Anneal all is no longer a problem with these.
Edit: For anyone interested - I have re-done the Wrye Bash Pictorial Guide ready for 292 release, most of the Basics and Intro to installers guide has been overhauled, with an extra screen for Basics (decided to add another Saves Tab screen highlighting the repair ABomb option), but saw no need to update screen 6 because none of the new changes to Wrye Bash change anything there ( and to be honest making that screen keeping it colour blind friendly is a pain

). The Installers Advanced pdf will be re-upped aswell, not due to any changes in Wrye Bash but because there was one remaining typo and it was bugging me. Will upload around the same time as Wrye Bash 292 (otherwise 291 users will be wondering where all these new screens and options are).
I also changed screen 4 of the Intro to Installers section - It was a bit confused looking and the UOPS is in the wrong Install Order position.
Also re-vamped screen 4 of the basics guide for now, but I can whip that out at the last minute if we get a fully functional CBash.
That new Installers option in the screenshot above has been left un-selected for the Guide, since most people will not be needing it on.