This is more a discovery than a question but thought it would be of
interest. And possibly its all old news, though I could see no specific

We are converting one very complex screen with lots of objects on. It is
written in PFC. The App was working painfully slow.

The issue was that everytime you navigate it would utilise the standard PFC
save functionality LUW and check that no updates are pending. This was
where our performance bottleneck was. It would take between 1 and 3 seconds
to do this (its almost instantaneous in PB client). After much trial and
errore we tried the w_masters of_setupdateobjects function and it made a
world of difference. We have sub second fast response times now.

We have needed to use of_setupdateobjects in the past but it makes such a
difference on some of our "Heavy Windows" that I will be definitely using
from now on. It works because simply tell the save process exactly which
controls to update, rather than having it search through all controls on the
window, sometimes even drilling thru layers for user objects, tabs etc as it
was in my case.

And onwards...