Yeah, don't forget to retract the shoes Isaac. After a while there gets a nice groove in the drum that makes the shoes about as good a retaining ring as can be.
I wouldn't worry too much about heating the brake pads, asbestos is good about tolerating it afterall. The heat is probably more problem for the paint and grease in the area than the shoe material. You do want to be mindful about breathing in the brake dust, though.
BTW, factory mini truck drums have the holes for extraction, although some aftermarket ones do not.
"Silent enim leges inter arma." -- Cicero