As I know it is possible, but I need some details.
I have such BFDAT
ADD-BFDAT:25,HG3550&HG3530&SIP,BCHL60,;
CHANGE-BFDAT:CONT,25,HG3550,1,1,;
CHANGE-BFDAT:CONT,25,HG3530,150,,30;
CHANGE-BFDAT:CONT,25,SIP,80,,20;
CHANGE-BFDAT:OK,25,YES;
which assumes only 10 B-Channels (CHANGE-BFDAT:CONT,25,HG3550,1,1,
I think I need to increase it to 20 B-Channels and create ordinary TDCSU with BCGR=2 and no LWPAR.