First off, the newest version of PBP3.1 does indeed support the Qxx families. If you still use PBP 3.0 you will need to upgrade. If you already have PBP 3.1, just go to the ME Labs site & download the free update.

Secondly, receiving data from several UART sources is easy. Just create variables/buffers to store the data as it comes in, then filter through at your convenience. I would use interrupt driven RX so no data is lost (as opposed to polling). This is a job for DT_Interrupts or ASM interrupts (definitely not "ON INTERRUPT GOTO").

Thirdly, since the newest PBP 3.1 supports the Q43, your other question becomes irrelevant.