Folder Tree jumps to the right side in Dual Horizontal mode

In Dual Horizontal file display mode with the Open second Folder Tree in dual display mode preference enabled, closing the first (top) Folder Tree will cause the remaining Folder Tree to move and display along the right side of the lister. In comparison, when closing the second Folder Tree instead, the remaining top Folder Tree will just expand to the bottom, remaining in place along the left of the lister.

I believe the scenario when the Folder Tree moves to the right side isn't intentional, as I don't see a way to achieve this Folder Tree position by choice. My expectation is that the remaining lister, no matter which is closed, would simply expand upward/downward and remain on the left.

Thanks.

- Directory Opus v12.23.2 Beta x64 Build 7734
- Windows 10 v20H2 OS Build 19042.868

It is intentional, and has always done that. I think it's to indicate that that tree is connected to the second display.

(It is a bit weird, but so is using dual-horizontal with only the second tree. :))

That makes some sense. Though if that's the case, I still I think there could be a better approach. Should you ever choose to update this behaviour, I suggest, for example, for the Folder Trees to be suffixed with "(top)"/"(bottom)" instead, or just the letters T/B (and L/R when vertically split), and keep them in place, rather than moving their position to help indicate File Display association.

My argument for this is that, in all other scenarios as far as I'm aware, the Folder Trees are connected on the left of their associated File Display: even when in Dual Vertical mode and the left display's Folder Tree is closed, the right display's Folder Tree doesn't move to the right side of the lister. In this state (one Folder Tree between a left and right display), it could be argued that it's potentially equally confusing to the user to determine which File Display the tree actually belongs to, so why it doesn't move to the right (for the reasons you recalled) like it does in Dual Horizontal is a little odd to me.

I understand wanting to keep things as they've always been, as over the years, many may have already become accustomed to this, and now that I know it is expected, I can live with it too. So I guess issue really is: the inconsistency can be interpreted as a bug, or something possibly broken, which is typically desirable to avoid.

All in all, it's not a showstopper. Just something you may wish to consider at a later time.