Didn’t think of that! Not quite the same visual effect, but good enough for me. Thanks!!
Switch item=U1gangway visibility=[U1gangway_manual!=ON]
Text item=U1gangway label="Unit1 gangway (manual mode) [%s]" visibility=[U1gangway_manual==ON]
Edit - and with a littl experimentation
Text item=U1gangway label="Unit 1 gangway [manually %s]" visibility=[U1gangway_manual==ON]
displays name to the left and manually ON to the right