The list I provided a few years ago in the post linked below is probably still reasonably accurate:
We have done a few things since that list, I think:
– Repeat markers (D.C./D.S./Coda etc.) are now exported
– Fingering is exported
– Figured bass is exported
– Time signature export has been improved such that common/cut-common signatures are handled better
– Some improvements to complex multi-voice tuplet export
– Fixes for octave transposing clefs when exporting
There remains a great deal to do, no doubt, both in terms of import and export.