There may be some differences, since I am messing around in pathfinder, but it seems like the XML custom output just uses the original descript field.
It does seem to use the livename field for the name, and adding a spell descriptor tag (like the good or evil descriptors) using sDescript.Good is added to the xml output.
If 5E doesn't have spell descriptors, maybe add a new school tag for Rituals, if that gets added to output.
You can limit the changes to output only by checking for state.isoutput like this:
Code:
if (state.isoutput <> 0)
~ make whatever changes
endif
That way if you want to make a change to the spell's livename (for example) for the xml output that you don't want to show up within the regular app, you can. The changes would show up on all types of 'output', like the printed character sheet(s) and stat blocks too.