[...]

[activity]
device       = bthsp
sink-name    = equals:sink.primary
active       = sink-name@equals:"sink.fake.sco", property:"bluetooth.hsp.prevent.suspend.transport", value@constant:"true"
inactive     = sink-name@equals:"sink.fake.sco", property:"bluetooth.hsp.prevent.suspend.transport", value@constant:"true"


[...]