peter After many more hours on the weekend, I think I have now a workaround in place that is satisfactory. Implemented in build 2488.
Just Tested IPhone zoom, yes it’s perfect with reliability of pinch and zoom, I can use it now.
I found it takes up to six pinches to get from full zoom in to zoom out this would be much better if it took two at maximum three.
Another new discovery is the double tap to have a segment appear in full view , which by the way is very nice to have, I found the first and last segment it does the opposite, it zooms out completely and they are normally the smallest segments being an intro & end , so they are most likely the ones you need to zoom in on.
Also the second last segment on both songs I tested it on zoom in to the beginning of this segment and doesn't show the end of this segment like all others.
Fantastic job, now I actually like the iPhone editor in portrait mode almost as much as my iPad in landscape because the zoom is fixed.
Just to add an observation, I noticed when you pinch zoom with two fingers the whole interface moves up down as well , but there’s no need for it to move as I can see all necessary
Options , it only needs to move when options are off screen, like in landscape mode where you have things you might need to drag up to use.
By it moving all the time it unnecessarily wobbles on screen when pinch zooming.