Hi Wolfgang, as I reported the issue with the fonts and LMTX, I remembered two suggestions I wanted to post here. The first one is enabling the use of "method=uppercase" in \definefallbackfamily (to get fake caps, such as in https://mailman.ntg.nl/pipermail/ntg-context/2018/092878.html). The second feature is to enable \definefontfamily to load font files not part of the font database, the same way as \definefont is able to load them. Many thanks for your help, Pablo -- http://www.ousia.tk