When did hiding the sidebar list start resizing the window?

When using Show/Hide List the window size previously kept the same dimensions.

At some point, the behaviour changed to having the window resize – which I guess the intention is to keep the Edit/Preview width the same:

Would it be possible to have an option to make the window remain the same size?

Although at the moment, even if you prefer the window resizing, reopening the sidebar doesn’t open to what it was initially either:

That was something that went in a month or so ago. Let me work on giving you an option here.

Try the new beta and see if this helps.

Works well, thank you.