I've never even seen an HDX82, but I'm certain the TV not the remote makes the connection between the input key and the following digit.

For practical macros, it doesn't matter that much. The value of a discrete is in writing macros that don't need to know the prior state. If you can do input select in two macro steps not knowing the prior state, that's not much worse than doing it in one step. I wisk MY Toshiba TV could do so well.