I thought the info panel would automatically become a 4th column if the editor was wide enough? Am I not doing something correctly?
It is not possible. Although it was tentatively suggested by developers (and I saw it implemented on development/internal version of Panda preview screenshot somewhere here on this forum), this feature is unfortunately not implemented yet.
You can still tear out the mini-window and use it as separate window (if you need so). But I agree that especially with ToCs and Backlinks, the real value of 4th column (in mac app at least) would be profound.
Recenly, on reddit @trix180 mentioned “We have not received a lot of requests for backlinks enhancements to be honest” but I am sure that this is rather false logic - that it is basically not so good implementation of INTERFACE of backlinks (and ToC) which prevents users to use them more. Function-wise, they are enough for me, I do not need more functions like filtering or search in Backlinks (I can still do it in normal Bear search if needed). But putting backlinks here on this least visible/most hidden place of the app is like installing car radio under the spare tyre in the trunk of your car and later suggest that it seems that people are not using car radio so much at all, so there is not sense to move it on better place… The reason why they are not using it is obvious in this case. And even users who do not use Backlinks, they would really appreciate Table of Contents of longer documents in this side-by-side layout (like on wikipedia or word etc), I am sure.
Thanks for the clarification!