Yes, with this (> 500 characters)
c:\Users\florian\TestFiles\MP3\012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789\001 012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789 012345.mp3
It works both in foobar2000 and Picard, the former displaying the file path in the 8.3 notation C:\Users\florian\TESTFI~1\MP3\012345~1\001012~1.MP3, the latter in the long filename notation as \\?\C:\...
I basically had to re-implement everything drag and drop related due to repeated crashes with the framework-provided solution I used before. Here is the protocol of this daunting process for reference:
Unfortunately, due to the inherent issues with this solution, there is no going back.