Sorry for my late response. I read your points and what I am asking is something different. Do correct me if I am going on the wrong path.
I don’t change Tor browser window size or modify anything as I am familiar about how this can backfire and compromise user privacy. What I am saying is that on a 1440p monitor, the Workstation size is smaller by default and this reduces the size of the browser to 720p.
What I did is not to alter the browser in any manner. But only resized the Workstation window size in order to get a browser resolution of 1000 x 1000 instead of 720p.
Basically the Workstation window starts smaller on Virtual Box which in turn reduces the Tor Browser window size even when the host machine is having a 1440p res.
Does this make any sense? Do let me know. And thank you again!