I agree with you. There should be easier options to work with tied notes.
Currently, I do all the necessary changes like adding dynamics, etc. before I tie the notes together. As well it is possible to re-enter the write mode Shift/Cmd + n and enter there a cresc or other stuff.
Currently, it bothers me most that it is not possible to select parts of tied notes, e.g. a complete bar with a whole note that is tied from the previous bar into that one, to copy it into another position. When I copy a complete handwritten score and I know that certain phrases are doubled partly in other instruments I must not tie the notes, but first finish everything, do the necessary copy operations and the hopefully not forget the final tieing of notes.
I understand the motivation within Dorico how tied notes are handled. BUT for human readability (and because of other reasons) bar lines were added somewhere in the 15th or 16th century and so we read them still in bars. And I don’t see any reason why it should not be possible just to select a part of a tied note. There may be users, that think always in lengthy tied notes, but I am sure, that there is quite a number of users, that think differently.
I would not go so far, that I would go back to Sibelius - I never used Finale -, if this is not solved. I started about 1992 with Score and it was great at that time and it offered a huge flexibility even that one had to learn all the codes to use it effectively. But as soon Sibelius 1.0 was out, I immediately switched and never went back and I was happy at that time. And now because of the much better usability concept, I love Dorico (even that certain features are missing. That is fine for me because software development takes time.).
But when I would be asked, what do you don’t like within Dorico? For me, the only pain point is, how strictly tied notes are handled.