probe the brisket, temp the corned beef?

When making pastrami from corned beef many people, myself included, take it too 165 +/- then cool it, then steam it for a couple of hours before serving. This replicates the traditional way pastrami is served in NY delis. Some folks finish them on the grill and that could involve wrapping or not, but probing just like brisket.

The enzymes from the corning process break the muscle fibers down and makes it more tender at lower temps. But, I like taking my corned beef closer to the 180* range.