ornaments are placed outside of octave lines


In the screenshot, ornaments are placed outside of octave lines. In this case: trills on above the 8va.

I think all trill markings should be below the 8va…
Could I control it not using Engrave mode?

No, you have to adjust them in Engrave mode, at least for now. Slurs, octave lines, tuplets and articulations are all positioned together, and other items (such as ornaments, playing techniques, etc.) have to go either inside all of these things or outside all of them. We expect this is an area we will revisit in a future version.