hotdog,
The advance unit is intended for people who need to replace their advance anyway due to age and condition and for those who prefer an electronic advance when they buy a new electronic ignition system. It will not do any more than the mechanical advance and if you are happy with your mechanical advance, then you won't need the electronic version.
I originally introduced the PAMCO ignition so people, including me, could spend their Saturdays riding instead of screwing with the points. Now, I see a lot of threads where people are spending their Saturday mornings screwing with the advance weights and springs instead of riding even though they have a PAMCO , so it was just time to introduce the electronic advance.
In answer to your question about starting with a PMA kick only, the basic sensor pulse from the PAMCO will arrive in the electronic advancer fully advanced, but the advancer is really just a delay circuit, so the output will be delayed to position the timing at idle. This delay is then decreased as the RPM's increase until there is no delay at 3,000 RPM and the fully advanced signal will go through the advancer with no delay. It's pretty much the same approach that most electronic ignitions with electronic advance use.