Blades
"everyone can make it work for own CS" - sure, maybe, but what about USERS that just want their stuff to work that doesn't?
With BCF2000 you are Behringer's user. CW does not get paid for these devices. There are devices which explicitly declare Sonar support (like Nektar Impact), other do not. You can not make CW responsible for all products from other companies.
I don't know C++ and don't really want to in order to get a BFC2000 to work with Sonar, which it should have done to begin with! :)
You can also ask someone else. But can you without a reason write me a good song, record and give it to me for free for commercial use? May be you can, but I do not think you will. And that is what you are asking from software programmers(from CW or community), till you complain to the producer of your controller (which get money from you to control parameters in software, since these devices can not do anything else).
Especially since it used to work and has been broken with no regard!
That is not really true. Before it was different program with different functionality. In respect to EQ, there was one (and only one) "filter", EQ. If in your PC you leave EQ only (and even in case there are other, but EQ is the first in PC chain), this EQ should work as before (it has a bit different parameters since it is "new", so may be not exactly as before). But in case you want use new features in new SONAR, you can not expect all old staff will work with that correctly "out of the box".
As I can see, you pay for your site, most probably you have paid for your site design. So you know IT people refuse to work for free

Even you "annoys" your visitors with advertisements and proposal to donate for the time spend for the site, can you imagine what proper CS plug-in development costs ?