Many communities already use letters instead of numbers for the backlinks. On the one hand this seems to improve the readability a bit and shortens the rendered output. It also would help freeing up the numbering system for sub-references.

For the general idea to get rid of the arcane mechanism to write out all possible backllink markers in a message this could be a first step into the right direction.

Implementation

• Provide a Configuration where wikis can default back to numbers ( ideally already preparing the config for the CLDR change )
• Asses the number of wikis affected by the change
• Develop a communication strategy for the change
• Change the default and set the fallback for the wikis that decline the change