More on this method.

It appears that the most successful way of pulling this off is to press "dim" and IMMEDIATELY block the stream for a moment (very fast, but longer than it was active), then unblock, block, and unblock and keep unblocked. By interrupting the stream twice, well timed, I get good results. Blocking once gives you a dim that stutters, blocking 3 or 4 times gives desired results (but not always -- you need to make you "blocking" time more than a moment, but short enough that the pronto keeps recording).

It's very hard and took me 2 hours to get it to work, but you CAN end up with a working dim/bright.

When we all get software, I'll "trade" my setting for others to use.