However, my opinion is that your solution just proves that there are not enough physical buttons. Take Situation A. While watching a program the Tivo remote gives you a dedicated set of program navigation buttons (FF, REW and so on). So, only one key press is needed to (say) fast forward. You have to press three buttons to do the same thing. This may not sound like much of a hardship, but notice that the only reason for the extra button presses is to change the mode of the remote so that the single pad of keys is mapped to program navigation.
I accept that all practical remotes need to have mode change commands that remap some buttons to a set of functions (otherwise, to have a dedicated key for every function would require 50 or more keys and the remote becomes big, unattractive and difficult - or impossible - to learn to operate by feel only). The full spectrum of possible remotes includes ones with from 50+ physical buttons down to ones with only 2 physical buttons. At one extreme, there would be 50 to 60 keys each dedicated to one function - and no remapping. At the other extreme there would be one button and a second one to remap the one button to the 50+ functions you need to perform - involving a constant, massive number of key presses to remap the one button to the right mode so that you could press it once.
Of course these extremes are both silly. But the question is - "Where on this spectrum is the ideal place?" In other words what is the optimum balance of physical simplicity (fewer buttons) and power (less mode switching). My answer to this is that when you are in any particular mode you should be able to do all the common things in that mode without changing modes. Changing modes should be restricted to situations where you are logically changing modes (like going from watching a program to choosing programs to record) or are doing something that is done infrequently.
In my case, while watching a program on Tivo, the most common thing I do is some sort of navigation within the program (FF through ads, rewind to watch something I miss and so on). That's why I want a dedicated set of buttons to do those things. On the Tivo remote I can do any of these things in one press. Your setup requires three presses - because you have to change mode to map the direction keys to program navigation.
Your setup is the latest of several I have looked at based on my principles - in every case my conclusion is that the optimum balance of fewer keys and minimum mode swhitching requires more keys than Harmony currently has.
One final thought. When I go on vacation I have to show my house sitter how to operate my AV setup. It is difficult enough to tell them how to operate the Tivo remote where the instructions are "when you want to skip some ads just press FF". Imagine how difficult it would be if I had to say "when you want to skip some ads just press Play then press Help then press FF". I don't think they would get to watch much Tivo!
If Harmony meets your needs as it is, I'm happy for you. But if, like me and several others, you can agree that it is a potential breakthrough product that needs significant change to fulfill its potential, then join the "give us a few more buttons" pressure group. I'm sure someone is going to do it soon. The only question is, will it be Harmony that gets what the mass market wants before somebody else steals their good stuff and add the extra direction pad?
