I noticed that SD generated FPL's through Slovenian airspace will never be accepted because SD uses 'coordinates' rather than official entry/exit points. (I had one unaltered SD generated plan rejected recently for this reason). Slovenian AIP:

REF AIP SLOVENIA ENR 1.10 PARA 1.3. B. SPECIALARANGEMENTS FOR IFR AND VFR FLIGHTS (ICAO NOTIFICATION OF DIFFERENCE) FLIGHTPLANS WITH FLIGHT ROUTES CROSSING FIR LJLA BOUNDARY OR VOLUMES OF CONTROLAIRSPACE SHALL INCLUDE OFFICIALLY PUBLISHED ENTRY/EXIT REPORTING POINTS.COORDINATES OR ANY OTHER NAMES ARE NOT ALLOWED THEREFORE SUCH FPL WILL BEREJECTED.

.. not sure what we can do about that in SD. I guess we have to remember to make manual changes to the plans.

Just to give additional feedback: My original post here came after I failed to put the entry/exit point names into the route section of an FPL for crossing Slovenian airspace. The FPL was rejected and they asked me for the point names (ALIVO, RADLY). After SD updated the mapping I created the same route again to test it, and it does put the Entry/Exit points like ALIVO and RADLY into the route section, which is what the Slovenian's want according to the ENR exception. So it should be compliant now.

However, I note that SD still puts other 'inland' vfr points (like TREBNJE) in as coordinates. That seems compliant but I'll be interested to know whether such an FPL with mixed names/coordinates gets accepted. It should do because the ENR exception only references entry/exit points being passed as names, but on the phone I had to give names for all the inland vfr points.