[NTG-context] alignment of figures

Dear list members, I want to have figures arranged as follows: 1. Figures smaller than 0.5 textwidth at the inner margin, text flowing arround figure. 2. Between 0.5 and 1*textwidth in the middle, no text flowing. 3.Figures wider than textwidth aligned with the inner margin of the textblock and sticking out into the (wide) outer margin. I found out how to do the first 2 (from "Details") but couldn't figure out the last one. Any suggestions? Thanks a lot. Jörg