I've now moved the majority of widgets from static to dynamic. Not surprisingly, load times have improved a lot (50-100%). More surprisingly, run times within the application have not noticeably (i.e. to the naked eye) worsened and, indeed, some aspects seem much quicker (e.g. removing widgets rather than making them invisible). So, that's all good.

But there is a big problem: dynamic widgets are always placed right at the front when created, and I'm pretty sure that there is no way to move them backwards. This is a real pain because it means that any widget that one wants placed in front of the dynamic widgets a) has to be a dynamic widget itself and b) keeps of having to be destroyed and re-created to keep it at the front.

For example, I use a whole bunch of widgets to draw graphs and have grid lines which have to sit in front of the graphs plus a 99% transparent button sitting in front of the whole thing (to hide the graphs when pressed). All these latter panels/buttons functionally exist all the time and never move or change but technically I now have to keep destroying and re-creating them.