When establishing a frequency in SPI, don't I need setting by a PPRX terminal?
No. With SP0=SP1=1 all register programming is via the SPI pins (CS, SCLK and SDIO).
The PPRx pins allow you to automatically select predetermined device configurations by connecting resistors of certain values from GND or VDD to the PPRx pins. The PPRx pin configurations only matter when SP0=SP1=float. Furthermore, the PPRx pins get scanned for resistor connections only at power up.