The way we have been using them so far is to have all elements with a new status. Then, any of the renovation styles which need to show new elements are set to show them as is - no filter applied. This way, we have the most control over line types, weights, colors on the screen, etc. for the most important elements on the drawings - the new stuff.
Existing elements then have a filter applied - the pen color is overridden so that they all show up grayed out, but their line types are not so that dashed, dotted lines etc are still displayed.
Demo items also have a filter applied, so that the line types are overridden to be dash-dotted, and the pens overridden too, to be a single heavier line.
As I've used them, I realize I really only use three filters for CDs...
Existing Demolished New
DEMO Override Override Hide
NEW Override Hide Show
DEMO+NEW Override Override Show
I have some other filter combinations set up, but they are more just working combinations for use during the design/drafting process. I almost never need to show an existing only plan - for CDs the demo plan shows the existing conditions.
Hope this helps.
Bill
Bill Szustak RA
Principal, Springboard Design
ArchiCAD 25, macOS Ventura 13.4.1