I'm new to the Wing but the "set cruise, hold throttle, press acl/res" is the same thing I did on the Venture I'd been riding the last 4 years. Have been doing it on the Wing since I got it a couple of thousand miles ago.
Adjustment is down by throttle linkage not behind dash. Look where throttle cables hook to linkage and find cruise cable. This is where adjustments must be made. This also applys to automobiles as well. Loose cable causes lag and speed variation when set.