The defaults for a Dymo Duo 450 label file only allow printing up to a page length of 106.67", despite Dymo selling 300' continuous rolls.
Custom PPD file allowing user to create custom paper sizes within MacOS up to a total length of 300'
It is also worth noting that the "Continuous Wide" page size in this PPD has been changed from its default to 300' - this was in initial testing.
If this line still is here, it means that this has not been fully tested yet and I'm waiting on paper to arrive.