Thanks to Silvester on QL Forum, v2.18 of the Trump Card ROM is now available.
Upon a RES_128 it now doesn’t add anything, this allows 128K only MDV programs to run on machines which also expect JS rom. It just shows banner/memory and returns with no FLP/TK2 etc.
Download from http://www.dilwyn.me.uk/qlrom/index.html or http://www.greybeardz.com/qlrom/index.html. On both sites, the download should be in the same place, in the Assorted ROM Images section, labelled TC218.zip