Query Current Bed Temp for Conditional Gcode?

In SS / PS with my Duet3D powered printer, I use conditional gcode to look at the current bed temp and decide whether it is cold and needs a longer heat soak, or if it is already hot and can start a print immediately:

{"if heat.heaters[0].current < "}[first_layer_bed_temperature]-1.5
{"	"}M190 R[first_layer_bed_temperature]                                ; Wait for cold bed
{"	"}G4 S440                                 ; Cold Pause
{"else "}
{"	"}M190 R[first_layer_bed_temperature]                               ; Wait for hot bed
{"	"}G4 S1                                  ; Hot Pause

Does anyone know if there is a system variable in the Bambu firmware that we can query to get the current bed temp?