Well, to paraphrase Barbie "Math is hard" , so I wrote a new plugin: Pause at Layer
Ok, basically I just took Pause at Height and modified it to work off Cura GUI Layer numbers instead of Z mm values....
For anyone interested, I'm happy to share the code here or anywhere it is appropriate to do so. Just let me know.
Example print:
I didn't get all the Black out of the print head before printing with Golden, so there's a bit of a bleed-in between the two. My bad, not the plugin's.