I'm using 10 Pro build 19041.450 and resizing worked ok - though I'm not sure version of windows might necessarily be the issue.

Sounds like from https://store.stardock.com/policy.aspx you might need to give tech support a try anyway

Did you try restarting your computer after installing it? Generally it also does help to have your PC and drivers etc. up to date, but again I'm not saying that would necessarily help, just helps eliminate any issues that those might be causing. 

I feel you though, sometimes it's a real bother/pain to go through troubleshooting stuff.

If the built in resizing doesn't work, there's also the option of just setting your own large images for the cursors, I just tried and could actually put any size image I liked as a cursor using the 'Create Cursor' button.

Good luck

Thanks for your reply! I contacted support and I'm waiting for what they have to say. I did try many things to make it work, I tried to reboot, restore Windows, run it as administrator, update Nvidia drivers (now I'm using 452.06v), and even downgrade to an older Windows 10 build, and in the process I found a few graphical glitches (blinking cursor, randomly changing its size, and at some point it disappeared, I had no cursor until I rebooted).

For now, I think I'll be better asking for a refund.