sorry, should be ". . . less relevant question from the current topic? "
Totally relevant, here. What you propose to do is one of the things I did, ten or fifteen years ago. It works, and is often easier than manually lettering or numbering such lists. (I am still combing through the Wayback Machine looking for off-site references to posts about the discussions we had back then, about how to add kinds of complex-script auto-numbering and auto-lettering lists to InDesign without using edited fonts.)
Speaking as someone who has had to work with these kinds of homebrew or hacked fonts at great length, I would implore you to rename your font in all the relevant font fields in FontLab. I've spent way too much time in this life fighting with multiple versions of Zawgyi-One or KNU that have identical names but different glyph complements.