{"order": "/*{m:/}*/"} should be working. That is referencing the entire message not just one field.
{ "order": "[/*{s:MSH}*/", "[/*{s:PID}*/", "[/*{s:ORC}*/","[/*{s:OBR}*/",]} would not pull in your changes as it is referencing the source message.
{s:MSH} would pull the MSH from the source which is a read only copy.
{m:MSH} would pull the MSH from your message that you modified.
Try this and see if this works as expected:
{ "order": "[/*{m:MSH}*/", "[/*{m:PID}*/", "[/*{m:ORC}*/","[/*{m:OBR}*/",]}
One other thing to verify is in the visual channel editor that the destination is connected to the mapping node and not skipping. It can appear to be connected but skip it. You can do this by moving the mapping node and make sure the lines and arrows follow your mapping node.