It somehow seemed appropriate to use the standard MPCNC Crown drawing for the first vinyl cutting test:
That’s a PNG converted from the SVG original, because WordPress regards SVG and DXF files as security risks.
Run the DXF through dxf2gcode (from the Ubuntu repository) to produce G-Code suitable for my MPCNC’s GRBL controller, tape a sheet of paper to a sacrificial acrylic sheet, fire up bCNC, set the origins, and run the G-Code:
As expected, the cut paper pulled off the acrylic, because it’s not glued down; I have some Cricut adhesive cutting mats which are definitely in the nature of fine tuning. In any event, the paper showed I could get from a DXF image to drag knife cutting action.
This being a crown, gaudy gold vinyl seemed appropriate:
The weeding process removes everything that’s not the crown; I used a razor knife to cut a square and remove the vinyl around the crown. A good needle-nose tweezer works wonders!
Apply transfer film to the weeded crown and peel it from its backing paper:
Stick it on something desperately in need of decoration and peel off the transfer film:
The tricky part is setting the drag knife cutting depth to match the vinyl sheet thickness (14 mil = 0.36 mm), so the blade cuts the vinyl without cutting through the backing paper. This seems best done with manual trial cuts on scrap vinyl, pressing the drag knife holder down firmly by hand and tweaking the depth adjustment for a clean cut.
The G-Code cuts at 400 mm/min = 6.7 mm/s, perhaps a bit on the slow side.
The Smell of Molten Projects in the Morning 
Hackaday had a recent post on using this on adhesive copper sheet to make printed circuit boards. Sounded like a painful process to me but at least, no chemicals.
For the record: Copper tape synth
Laying out conductors using narrow copper tape makes much more sense than what I imagined: drag-knifing a big sheet of copper foil like it was vinyl film!
This is the one I was thinking of: https://hackaday.com/2018/10/28/making-pcbs-with-a-cutting-plotter/
Wow! Much better than I expected!
I have a 2 inch roll of 1.5 mil copper tape which feels like armor plate compared to 14 mil vinyl.
A quick eBay check shows copper gilding foil (some labeled “edible” which I straight up do not trust) of unknown thickness. For 2.50/100 sheets, it can’t possibly be very thick and I’m not sure it’s even copper.
Thanks for the suggestion!
And, I agree about the tape. Probably makes more sense. But, you never know until you try. Or, maybe past generalized experience means you do “know” but are still sometimes subject to occasional surprise.