The code in tmprint.red can at present be upset by various flags. Eg !*fort, !*list interact badly. Ideally in the end it will be rewoirked to be fully robust!
I have just fixed that "on fort" forces an "off fancy" if fancy mode was enabled then, and then "off fort" enabled fancy mode if it had been enabled when "on fort" was seen. But this feels not quite good enough to cope with e.g. "on fancy; on fort; on fort; … on fancy; … off fort;". And I bet that all sorts of other output-related flage really also need attention too.
Does anybody have either a good idea to make things rational EASILY, or the energy to hunt through and first catalogue the interactions, then propose what behaviour would make best sense and finallty implement it…