Awesome. Thanks!

I'd like to propose one button shows a list of immutable built-in presets, like before you implemented save feature. Another button beside it shows the save buttons and any custom presets.

Please let me know how you would feel about that. My opinion is it reduces the complexity of both the UI the code requirements.

I know it will simplify lot of things in code. I care more about the usability then code complexity. My idea was to have as least buttons as possible.
But I would like to do a release with current "design" and gather some feedback from users on that.
Im pretty sure there will be some reviews / complains.
But maybe the idea with one button will be total fail and we can change it to your solution.
What you think?

I completely agree with the goal of trying to have as few buttons as possible. Just speaking about the UI and ignoring the code, the super-long list with a scrollbar feels kind of ugly and difficult against the otherwise crisp and simple interface. It seems like a good trade-off to use the available open space for a second button, allowing each list to stay short enough to not need scrolling.

In theory, I also like the idea of releasing for feedback. However as I move into refactoring the presets code, there is a lot tied into whether the defaults are editable. If it's likely we would decide to make them immutable again, it would help a lot if I could just peel that functionality off as I go.

We could also, for now, make the defaults immutable but still in the same list. That would allow removing "Reset" and "Reset all to default", which would at least shorten the list slightly and offer some of the back-end benefit. I think in that case, we could also reduce "Save" to just one button that functions like "Save as" and overwrites if they use a name already in the user list.

I'm not in a big hurry because my attention right now is on isolating the snap feature, but I will need some kind of decision on this. I'm just fine if you want to avoid feature changes for now. That's why I offered it as an idea instead of just doing it. I think I've presented my case well enough to comfortably back off for now if you still have reservations.

Go for it. I will release the version without your change to gather some feedback on that. If it will be negative or neutral I will merge your change.

I released 0.3.2.0 version. Lets see how people will like it.