The rendering speed of bbw4 32bit (it will be 64bit soon but speed will be the same) is now the same as Biab64 Audio > Export Song As wav files...
It is a touch faster than RealBand bbw2 32bit.
Biab renders the tracks to RAM as it's playing, it could be done this way with the Plugin's bbw4 (it could load the tracks direct to RAM and would need to send audio play/sync to the Plugin) but you would still need to render the tracks from RAM to wav then drag in the DAW.
Adar is making great steps in the programming of the Plugin.