I see, I believe he may have been asking to get more context, so he could determine better in what way it was working/not working for you, although I won’t speak on his behalf.
I am not sure why at this point you assumed I hadn’t tried it, but for clarities sake, I have. 
Since there is a sensible default in place and currently, the only way to change the width is by dragging, it seems unlikely to me that any user would somehow find themselves with a full width navigator while not knowing how that happened.
Also, since it is so easy to resize using dragging, I don’t see how it can be made more discoverable or intuitive to the user. Given most resizable sidebars work this way as a standard convention, if anyone familiar with modern UI wanted to change the width, they would most likely naturally attempt to drag it to resize.
Possibly the only case I could see, is in the scenario where a user accidentally resizes the responsive container in the canvas rather than the navigator (or vice versa), although this is an edge case (pun intended).
To be 100% clear, I am not claiming the Navigator is perfect, there is always room for improvements, new features and optimisations. That said, Cwicly have been refining this over many iterations based on user feedback and it is already much better than it has ever been.
Recent examples:
(one you are very familiar with)
For my day-to-day usage, there is only one major feature lacking in the Navigator at this stage, which is multiple selection. Once that is in place, everything else that can be added will be a useful enhancement.
And since the recent fixes, there is only one slightly annoying usability issue left, which is regarding the drag preview being incorrectly aligned when moving an item. This may be related to what you were mentioning and I will be raising this as a bug ASAP.
I appreciate that @Louis used the word first, I was just responding to it in kind.
Agreed!
I think Cwicly’s UI has many very intuitive and well thought out aspects and there may still be a few areas where this is not yet the case. By sharing your experiences with these I have every confidence their team will move things in the right direction.
No assumptions here, it isn’t a battle of right/wrong, your feedback is valuable and necessary. The more perspectives and viewpoints that are introduced, the more the UI can be refined and the better the tool can become for all of us.
My primary goals in these conversations is to help facilitate the above by isolating the crux of the issues and to help separate any already fixed issues and already included features from significant new points that the Cwicly team can then focus on including.
We are all passionate about what we want/need and I believe the best way for all of us to get more is by finding common ground and focusing on Win-Win outcomes.