Is there a way to implement a Point to Point transmission using P9T + BLX4R?
Sorry, there is not. There is no method of defeating tone-key squelch in the BLX4R receiver. This is required for point to point operation.
Options for point-to-point are the UHFR4 (all models) with the P9T; or ULXS4, ULXP4, or SLX4 in an overlapping frequency range with a P9T.