A quick confirmatory test here indicates that Dorico 3.5 works the same way as every other version of Dorico:
- Respelling in a score layout will update the part layout.
- Respelling in a part layout will not update the score layout.
- Once a note has been respelled in a part layout, it is unlinked - subsequent respelling in the score will not affect the part.
All of these statements are true regardless of the Set local properties setting.
All of these statements are true regardless of the Concert/Transposed pitch setting for either or both score and part layout.
If you have a Dorico project that contradicts any of this, please upload it to the forum.