Finding the optimal way to use MapMate party records is problematic because mapmate's database structure doesn't fit closely with the DDb's.
The problem is many (>20%) of mapmate party entries refer to more than one person - which breaks the one-to-one relationship between mapmate and DDb database entries. That said, for the majority of records, where a mapmate party is used to cite only a single individual or organisation then the information from the notes field could be valuable and worth trying to assimilate.
I originally tried to maintain the link closely (in which case the mapmate notes would have stayed connected) but the vast proliferation of duplicate entries forced me to change the design. Technical improvements since then may allow me to review the treatment of MapMate notes. Behind the scenes, the mapmate note fields are stored in the DDb and potentially could be re-incorporated.
Although not a solution for the wider (and useful) metadata that you mention I would definitely encourage people to include full names rather than initials in MapMate records - contrary to earlier guidelines from BSBI and BRC.
Thanks for raising this issue - it is worth reconsidering the current the situation.
Database Officer, Botanical Society of Britain and Ireland (BSBI)
c/o Centre for Ecology and Hydrology,Maclean Building, Crowmarsh Gifford, Wallingford, Oxon, OX10 8BB, UK.firstname.lastname@example.org