Hi @NatalieAtSafe,
I am using FME(R) 2016.0.1.0 (20160130 - Build 16174 - WIN64) desktop. In child workspace, i have changed the publish parameter type to 'Text (Multiline)'. In parent workspace, when i am passing two numbers comma separated in workspace runner, Comma automatically gets replaced by '<comma>'. Eg. I am passing '123,345' but it is passing '123<comma>345' to child transformer.