After a full week of operation, the capacitor fix and separate power supply continues to work well. I used the DirecTV guide screen as a test by scrolling up and down. I tried at least 100 keypresses each day for the past week. It is easy to watch the guide and see if the select bar moves with each command or not.

On five of the days I got 100% response. One day I missed one command. On the other day I lost three.

The problem could be with the DirecTV box, the remote, the RF linkage, the IR emitter on the DirecTV receiver or simple operator (that'd be me) counting error. In any case the error rate is too low to make it worth pursuing further.

I'm satisfied that these mods work and will not continue to overtly test the system further.