Document, window, and tabs management/rules?

Perhaps this is just a preview thing that is yet to be implemented, but I’m having trouble with managing/arranging windows and tabs in Preview 39 and 40.

There is a File menu item for a new file. There is a File menu item for New Tab (which appears to open another instance of the frontmost file in a second tab - cool feature). But for the life of me I can’t get different open files to display as tabs in the frontmost window.

Bike does not seem to follow the default setting from System Prefs > General > Prefer tabs:… And in Bike the Window > Merge All Windows menu item (to aggregate all open windows as tabs in the frontmost window, is grayed out. As a heavy multiple-files-open-in-tabs user (especially in TaskPaper) this is messing with my capacity to take Bike for a spin (pun intended), for how I would normally use an app like this.

Is this just on the to-do list (perhaps it is one of the things that does not come from free because of the custom editor?), or am I missing something here?

Otherwise, I think this is really slick and I’m looking forward to seeing how it develops. If my Mac in on, TaskPaper is running with many files open, so having a new app that may complement my TaskPaper uses is very exciting.

Thanks, this is a bug. Will fix for next release.

Thanks, and looking forward to the next release.