There is a bit of a learning curve - I use to print on the Dreamscape with a JV-33. It took a little bit of trial and error on the Mimaki to get the heat settings just right and I had to raise the head to the higher setting - but overall it was pretty straightforward.
Is there a head height adjustment on your Roland? I know a few sign shops that print A LOT of this material on their Rolands - but a different model printer than yours.