I have 5 of Aerobask's aircraft and a ton of XP11 aircraft, so I know how you feel. I'd love to have them be supported on XP12 NOW. Conversely, I hate CTDs and having to chase down errant addons. I imagine devs hate having to constantly debug addons because the sim changed. I'm willing to wait for solid products.
Aerobask uses Skunkcraft's updater to push updates (I wish more devs would). I want to say that most of the GA aircraft Aerobask creates don't go too deep into systems depth, but I won't cause I am clueless how much work really goes into developing aircraft. I believe that the Aerobask Diamond FADEC systems simplifies some programming, but again I don't really know. What I can says, is that I'm super impressed with TOGA's MU-2 and Hot Start's CL650. These look pretty complex to me.
I also have a few aircraft by Thranda. Thranda, as well as most devs, has chosen to wait, for the most part. I guess @Ben Russell summed it up in a word: Wisdom. In the end, we'll get the awesome aircraft we crave.
To Laminar Research: chop chop.