Enable TX interpolation in gnuradio gr-osmocom block

Hi ,
how can i use built in FPGA interpolator when using limesdr in gnuradio and gr-osmocom block ?
and same thing in RX mode and Decimation .

Another problem is gr-osmocom work properly just by setting channel bandwidth to 130Mhz . other bandwidth disturb signal , i have tried that with 5msps .

anyone have similar problem ?