Andrew My understandings or assumptions as a 'self taught user'. Haven't looked at your examples, so might be missing your points.
- preview above/below fall of the page (bug?) AFAIK all the previews below will be a single colour as defined by something like colour preview-below 80 #0 = black 100 = white, or colour preview-below [80 0 40]
(but I do have a longstanding bug, whereby colour preview-above [80 0 40]is completely ineffective, the above outline is always black, which is frustrating) ...
- can we have colour preview-above/below map to have the same colour preview as the offset part Would be nice, I have sometimes wanted the preview 'shadows' to be mixed with the particular scrap/map infill colour.
(although it seems that the programmer had not expected all levels to be displaces, so the 'shadow' is now not on the page, which must be a bug)
Probably more an unexpected use, that an offset passage would not be bounded by passages that are not offset, I think this was probably intentional. The way I use the corollary of this feature, preview, is to display nearby, overlaying and underlying passages for a distinct map that is the primary focus of the output. I definitely do not want the preview 'shadows' to cause Therion to extend the map or atlas boundaries. Would cause me all sorts of trouble. I have used preview above/below a lot, but have never figured out the significance of map level and how to use revise in this context, so will watch with interest. Bruce