I have similar issues with usability. I only use Windows 10 for a single purpose. When I have it running that's primary my focus. I have a 1366x768 display. I have my Windows 10 set to 1024x665, only other options are 1024x768 and 800x600. The 800x600 is just to small, the 1024x768 wraps the screen in Windows 10. So I live with the 1024x665 setting. I am uploading a screenshot, most that CPU activity is from Widows 10. As mentioned previously leaving Enable 3D Acceleration unchecked really helps display wise.
I guess that's to be expected when using free software. I wonder if premium VM software would be an improvement?
I doubt it unless you have a really heavy duty system. It works well enough for me on this computer if I just stick to using the Windows 10 virtual machine. Using several programs at once both in the host and guest can slow things down a bit. Like I said earlier I only use the Windows 10 vm for a single purpose. Everything else is done on my Slackware Linux host.
Just install it. Works. VirtualBox rarely notifies me of updates. Before updating, manually ran "Check for Updates..." says I am using latest version, only it was 6.1.8.
I know it's been a while since you posted this but I wondered if at the time you had tried installing Virtualbox Guest Additions? Among other things it allows you to drag and resize the Virtualbox guest window to any size and shape, automatically changing the guests resolution to match. It also comes with improved mouse pointer integration, optional shared clipboard, shared folders, seamless windows (worth looking at) and more. https://www.virtualbox.org/manual/ch04.html
VirtualBox gains support for Linux kernel 5.8 September 6, 2020 https://betanews.com/2020/09/06/virtualbox-linux-kernel-5-8/
I noticed that in the Changelog, that was pretty quick. My distribution is on 5.4.64 right now. Good to know I'm set if Patrick Volkerding decides to move to that kernel.
Downloaded yesterday, installed today. Was using a testing version because of the 10.5 bug. All is well again.
How does VirtualBox compare to VMware Workstation Player? I didn't even know that it was freeware. And I also wonder if you can still buy Win 10 Home, I searched for it but I saw all kinds of shady looking offers. https://www.vmware.com/products/workstation-player/workstation-player-evaluation.html
I don't use VMware so can't give a comparison. I did attempt to install it. The install fails. First because KVM in enbled (vmware-install log) on my system and second vmware 16 does not support my processor. As for Windows 10 Home, I found this: https://www.microsoft.com/en-us/p/windows-10-home/d76qx4bznwk4
OK thanks. I've already found a comparison and VMware Workstation Player doesn't support snapshots, what a joke. So I guess I will need to give VirtualBox a try. And yes, I knew that MS is still offering Win 10, but I was looking for a cheaper price, but the question is how trustworthy the cheaper versions are. https://www.nakivo.com/blog/vmware-workstation-pro-vs-player/