Depends on the block. Open decks with non siamesed cylinders need a torque plate to stabilize the cylinders during boring/honing. With siamesed cylinders+open deck you can get away without a plate, I wouldn't, but you can.
Regular closed deck blocks always need a torque plate.
IMHO any aluminum block needs to be finished with torque plates as well as every loaded fastener that goes into the block present and torqued to spec.
i have seen shops that specialize in ford mod motors not only use torque plates, but bolt up a drone oil pump (driven off the crank) to simulate the torque stress of that as well. the shop did that with one i had machined along with using ARP head and main studs and new side bolts for the mains.