it should also be noted that some of the controllers (like hold) don't have the whole range of values from 0 to 127... they are either on or off.

In those cases. any value in the lower half (0-63) will turn it OFF, and any value in the upper half of the range (64-127) will turn it on.

The link in the first post that leads to the list of continuous controllers should say which CCs work this way, and which ones have a variable range of values.