Is it possible to write an A flat tied to a G sharp, for example?
If I write the two notes with forced duration on, then select them and press T, they get rewritten as an A flat tied to another A flat.
I can fake it with a slur of course, but I shouldn’t have to do that, and it doesn’t play back correctly.
I think it’s only possible if the two notes are in different voices. You then tie them together by selecting the first note, Cmd/Ctrl+clicking the second note and then hitting T.
That works. Ironically the problem actually occurred on a voice staff - maybe that’s why I never thought of using two Dorico voices 
This only works in 12EDO, not in other tonality systems, even if every EDO has its own set of enharmonic equivalencies. So it must be faked with a slur.
Ah, so it does, in 24EDO. I didn’t check that. I’m in 22EDO, in which, for example, E and F-quarter-tone-flat are enharmonically the same pitch. Dorico does “know” that, plays the correct pitches etc., but refuses to tie them even if they’re in different voices.
In the project attached above, the notes weren’t even in different voices - I input them as a single note, switched to Engrave mode, grabbed the notehead at the start of bar 2 and respelled using Alt/Opt-=
I’m not sure if there’s a limitation I’ve not come up against, or if your pitch deltas aren’t set correctly. If you upload a small project that includes your tonality system then I’m sure someone will take a look.
It seems the limitation is that Dorico can’t handle the enharmonics in other systems than those that are multiples of 12-edo (24, 72 etc.). I made a sample project with sections in 12-, 17-, 22-, 15-, and 72-edo. Only in 12 and 72 can the enharmonic pitches be tied (from one voice to another). In each bar, the second and the third note are enharmonically the same. Where can I upload this project?
You can upload it simply here in the forum. The development team reads everything, and there are obviously several other users interested in this subject.
enharmonics.dorico (500.3 KB)
In each bar, the second and the third note are enharmonically equivalent.
