Yes and no.
Nothing logs at all when in Dev mode. (Certainly any profile hours and/or progress towards achievements, pretty sure it also messes with flights in Log book also.)
As for Add-Ons / Liveries etc.
These can and do inhibit progress towards certain achievements which is why there are many posts recommending you don’t try flights towards achievements when using them, however unless SU6/SU7 really changed stuff then flights should log perfectly fine in the log book and indeed while certain achievements may not progress the profile should actually also log hours and flights.