Q: What version of AX do you have to be in to upgrade?

The ideal scenario would be a “vanilla” implementation of AX 2012 R3, with no modifications, ISV’s or data integrations. However, in the real world, two surprising questions that need to be answered first are:
1) Should I upgrade to D365 or stabilize on AX R3?
2) Should I upgrade or do a re-implementation?

Simple charts that show the “available” upgrade paths based on AX version completely miss the complex questions that must be answered on a company-by-company basis.