Sometimes I want a new empty tab next to the one I'm currently on, because I want to browse something related. Other times I want a new empty tab at the end of the column/row of tabs (not near the current nearest tabs which are probably related to my current tab), because I want to browse something unrelated. These are two different actions and should have separate commands.
Because there is currently only one 'New Tab' command, whichever way I have the 'Open new tab next to current tab' setting, when I want do it the other way I have to do some little dance with activating other tabs or dragging tabs along for ages to get them in the right position.
So, please have two commands, with two keyboard shortcuts e.g Cmd-T and Cmd-Alt-T. The setting in Preferences can control which command is the 'default', i.e. bound to Cmd-T.
Similarly, another setting can control which command the + button on the address bar is bound to. The + button at the end of the tab bar could be bound to the other command, or the same command, depending on a setting. Whichever command a + button is bound to, holding the Alt key (or some other modifier) while clicking the button could perform the other command.
The tooltip for a + button should say which command it will perform, and give the keyboard shortcut, possibly with the modifier also suggested, e.g. "New Adjacent Tab (Cmd-T). Hold Alt for New Tab At End (Cmd-Alt-T)". Ok, maybe that's too long :/
Alternatively: the two commands could be "New Tab" and "New Child Tab". For me that's not quite as good, but it might be simpler in terms of preferences and shortcuts.
Thanks to Kagi for making such a superb product!