@demodemo M950 S0 for first, M950 S1 for second, where S is the servo number. Make separate deploy and retract Gcode files for each probe and servo; use deployprobe0.g and retractprobe0.g for probe 0, deployprobe1.g and retractprobe1.g for probe 1. Deploy and retract macros should reference the respective servo for each probe.
Ian