Different types of stacking - Main Panel / Panel Stacking

[Surobaki]

Good day,
I've submitted a question to the support forums (see below), and the response to my problem seems to have been to support a post to the wish forums here.

So, what I'd like to ask would be a possibility to keep the ratio of the panels the same (the width of say, the Main Panel and the Right Main Panel) after resizing the window. Currently, after switching out of full screen and back in, this ratio is reset to the default values and the Right Main Panel is very tiny relative to the Main Panel, whilst I'd like to to be around 50:50 with the Main Panel. The same could apply to the Left Main Panel.

That, or the ability to stack elements like files and playing tracks horizontally, side-by-side, instead of vertically as it is currently in the Main Panel. Both would fulfil the same purpose.

My problem, sourced from the support post:

My question:
Would it be possible to stack elements in the Main Panel in a manner so it's side-by-side?

Example problem:
Picture 1

I've also considered doing an alternative of keeping the file element in the Main Panel, whilst keeping the playing tracks element in the Right Main Panel. This works fine, however there is a minor issue with it. Whenever I resize the window and put it back to full screen, the resized Right Main Panel becomes small again, and not in the almost 50:50 ratio that I'd like to keep permanently with the two panels.

Alternative (after setting it up, without the default resizing):
Picture 2

Alternative (after I resized the window and went back to fullscreen):
Picture 3

Thank you very much.