Hi Graham, firstly let me state clearly that I am not at the level of some of these fine ladies and gents when it comes to DCC programming. I have forgotten a lot of what I learned some years back as DCC was becoming exciting and am returning to the hobby after an 8 year break. I am also operating a Massoth central station with a navigator.
Based on my own meandering experience the easiest and most satisfying way to approach these challenges is to sit down with a glass of something, your programming system and the CV details in the instructions and start playing. You would be surprised at how quickly you will pickup the variables just by programming in the areas you are interested in activating. Flashing for example is dealt with at the top of page 19 and applied to the CV values nominated at the top of the table. Page 4 suggests the A2 and A3 functions are the screw terminals which is what I would start with connecting to whatever it is you want to flash etc.... it is only if you want to add another 5 functions you need to consider the soldered pads.
It does require some application but once you "get it" is really is a lot simpler than it first seems.
. It's the 8122001. It looks like to get the extra features above F3 I have to attach wires to the solder pads on the back 
. It would be helpful if the booklet that came with it had a few step by step examples of how to programme the various outputs (as well as all the CV stuff).
