“Co-development” is a term similar to other terms that have been discussed at this table that don't necessarily have a clear definition or are situated in other federal law.
I'd also remark that “co-development” does not appear in UNDRIP itself. The terminology used in UNDRIP is really around consultation and co-operation, so for consistency with UNDRIP language, that would be the big consideration around the preference with regard to existing language on consultation and co-operation.