Be sure to use the Canon Printer utility that syncs mac OS updates with printer paper updates from MCT. You should start new papers in Canon's MCT and its in there you can define roll/sheet.
FYI This may not be your problem, but X-rite colormunki photo has a software issue that prevents new papers being profiled with pro 2/4k printers. Having setup a new custom paper in MCT, synced using printer utility, it fails to appear in munki's Printer settings Media Type drop-down when trying to print munki colour targets. There may be a workaround by saving targets to a PDF then printing from Photoshop, but not had time to verify. From the sounds of support (who having checked/confirmed my issue with 'corporate') gave a low chance of a fix as munki is....somewhat old (!). Still investigating, but since i1 is regularly updated this issue may not exist.