IMHO,
<element id="UseModernLayout">false</element> should apply to "tabs bar: horizontal", not only "tabs bar: Horizontal (Caption Bar)". This way, this new layout would be really optional.
<element id="UseModernLayout">true</element> should extend the tabs/tool bar in the right panel too, not only the left panel:
- since tabs bar and toolbar are merged in the new layout and when using a lot of tabs and toolbar buttons, the extra space on the ride side would be welcome. Having a lot of "..." at the end of each tab is not really wanted.
- Expanding / hidding the right panel should not modify the size of the tabs and move the position of the toolbar buttons/search box. It's quiete disturbing.
<element id="AllowStatusBarInPanel">true</element> should work with player controls on top too.
- Whatever the position of the player controls, the status bar doesn't need this extra space but the left/right panel does.
- And skinning wise, the left /right panel and the central panel could have a different color: atm, you have to choose the color of the central panel or the color of the left/right panel for the status bar.
<element id="ClassicNewTabButton">true</element> doesn't work anymore. Is it intended? I really don't like this "+" button. With this setting, I can hide or skin it and I'd really like the comeback of this setting: for me, a button like this is mandotory in a web browser, but useless in MusicBee because I don't use it every day: A right click, then a "add new tab" option in the drop down menu would be enough. But I guess some ppl use it a lot, that why I'd like the comeback of this setting.
If you want more vertical space, what about having an hide option for the header in album & tracks / tracks view like we have for artwork view?
With few columns displayed, you don't need this header to be always apparent since the content of those columns is obvious, while with a lot of columns displayed, it's better to have it always apparent (but I think that adding a horizontal scrollbar would be great: resizing a column or mouse over to see the tooltip isn't really friendly user).
If you don't want to implement this option, would you consider to add a gap setting between this new tabs/tool bar and the rest of the panel, plz? Some skins would take advange of more space between those two elements. IMO, there's not enough space between the tabs bar and the header bar of the central panel.