Great to hear that Greg and you are working on update ...
In the mean time, I did success to made a perfect print as usual on other printers.
So, I use mostly Verbatim full printable DVD.
Also using DVD with DVD case profile in Acoustica CD print, with last update of printer templates.
Choose Canon MG5350 printer template, full printable.
Then choose Edit printer template.
Diameter is 118 mm, and hole diameter is 21 mm.
Move to the left by 0,30 mm and move up by 30,00 mm.
That's it ... voila perfect print.
Please, check it in the way that check the print preview box in preferences.
Then push the show printable area button on top of preview page and you will see that now fit perfectly.
Hope that helped someone in some way.