Some nice links there, the Upverter one says this, but from 3 years ago
"WARNING: Upverter is in the process of overhauling our UPV format to a new version. We don't expect to maintain the current version, however we look forward to sharing our new version with you when it's ready to go!"- seems to have gone well off the boil, if nothing has appeared in 3 years ?
Meanwhile, a new trend appears - I see many Component Distributors are now moving into CAD, with some interesting moves around Libraries.
eg RS have ECAD Part Wizard which can browse by part code, and extract and export SCH and PCB symbols, in a few CAD formats.Presently, their ASCII format export choice is
PADS ASCII, which should not be too difficult to translate to KiCad.
(maybe someone with inside influence can get them to add kiCad directly..?)
This would open up a pretty broad WEB resource, to KiCad users, and save a lot of library time, plus they can port their
own libraries.
I like the idea of first doing a Library-based converter, as that keeps things simple, but saves significant time, and it is usually the Libraries Inertia effects that hold CAD users captive.
Full design convert can come off the back of the Library Converter code.
There is apparently some changes/improvements coming in eeschema SCH side,
http://ci.kicad-pcb.org/job/kicad-doxygen/ws/Documentation/doxygen/html/v5_road_map.html