If you would like to contribute to the RFC and get your voice heard the dicussion takes place on reddit at the following link.
Regional path aliases in APEX will behave same as traditional APRS. Each region will have an agreed on two letter alias that is case insensitive. As with the WIDE alias the format is SSN-n where SS is the two letter regional alias, and N and n are the number of desired hops.
The one exception is that for APEX compliance all path aliases must be reported in the ID packet periodically.