So far, nothing about this has been trivial.  Do you have any examples, or a good place to start my research?

I was following a sample that led me astray.  The drawphase needed to specify RowUIElement.  This is an interesting observer pattern to be able to not only control the context, but also the timing.  Anyway, it is working as I need it to now.

if (rowColRegionIntersectionUIElement == null) return DrawPhase.None;

return DrawPhase.AfterDrawElement;

Then,

var ultraGridRow = drawParams.Element.GetContext(typeof(UltraGridRow)) as UltraGridRow;

var bandIndex = ultraGridRow.Band.Index;

if (!(bandIndex == InitiativeActualBandIndex || bandIndex == ProjectActualBandIndex || bandIndex == ElementActualBandIndex)) return false;

if (activeRowUIElement == null) continue;

The RowScrollRegion contains the rows and columns and s not related to the band, so you will not be able to get a Band from a RowScrollRegion. A RowScrollRegion could display rows from any number of bands. 

You are drawing row borders using the RowScrollRegion element? 

drawParams.ControlElement.GetContext(typeof(UltraGridColumn)) == null ? "Null" : drawParams.Element.GetContext(typeof(UltraGridColumn)).GetType().Name));

Hi,

The DrawFilter applies to the whole grid. But you should be able to get the band from the UIElement - whatever element that my be - and thus do band specific drawing. 

It depends on the element, but I would try calling GetContext on the UIElement and pass in typeof(UltraGridBand). If that doesn't work, you could try UltraGridColumn or UltraGridRow, either of which has a Band property.