I have now updated the CHRONTXE.TTF file on the web.
The current version has many ligatures, including long s ligatures, with automated ligation and also has the sequences
thorn ae t
and
thorn a e t
both going to the abbreviation, which is the glyph which is also available directly at U+E75F, which is Alt 59231.
Hopefully some people with InDesign available will have a lot of fun with this font.
William