If neighbor cells have got same BCCH, regardless of their BSIC, there will be no handovers between them.
The feature Synchronized Radio Networks is just a name for HSN, MAIO and FNOFFSET planning.
I very much doubt that there is any possibility in GSM systems to survive with Co-BCCH/BSIC neighbors.
Because any feature can be applied on BSC/BTS level but MS will continue to measure the neighbors the same way and I dont think that by any kind of framing offset the MS can know who is who. (If both WHOs have got same BCCH)
Please correct me. Cause I am really curious about this.