Can the existing 'SERVESAS' tag be expanded to also work with SPELLS please?
This would allow sources that expect the OGL version of spells to be loaded with a homebrew alternative core set that replaces RSRD with full names of spells. The homebrew could then define named spells as 'SERVESAS:<ogl name>' for compatibility.
There are potential alternative methods, but expanding SERVESAS possibly works as a cleaner solution.
Expanding SERVESAS to other types (FEATS & EQUIPMENT) could also be beneficial.