Harp playing techniques position

Many playing techniques for the harp (e.g. Salzedo damps, thunder effect, eolic chords, etc.) “should” appear centered between both staves (like dynamics text) and should be independent of notes (like dynamics text). I can add a pp of a mf using any rest as reference, but I can’t add any playing technique that way.
The closest thing I could do was to input a note, add the technique symbol, delete the note without selecting the symbol, then edit the symbol properties (position: down). How can I position it centered between both staves?

Another issue: If I go to Engrave mode, I can see the technique symbol I just mentioned before, just below the rest. But when I return to Write mode, there’s no symbol. It’s just gone. If I switch back to Engrave mode, it’s still there. Why?

I don’t see any of these options in the expressions panel. Where do you find them?

They are not in the expressions panel; they’re in the Playing techniques panel.

My mistake as a long-time Finale user. I cannot find these harp techniques in the “Playing Techniques” panel. I am looking particularly in the Strings section of the latest upgrade (English implementation) for “Salzedo damps, thunder effect, eolic chords”; are they somewhere else or do I simply not recognize them?

Oh, they are in the Pitched Percussion section (don’t ask me why…).

Amazing. In other ways Dorico treats the Harp as a String instrument similar to violin.

It has to do with the fact that the harp is placed - and therefore grouped - with pitched percussion on a full score.