The situation on Windows got remarkably better and cheaper recently-ish with the addition of Azure code signing. Instead of hundreds or thousands for a cert it’s $10/month, if you meet the requirements (I think the business must have existed for some number of years first, and some other things).
If you go this route I highly recommend this article, because navigating through Azure to actually set it up is like getting through a maze. https://melatonin.dev/blog/code-signing-on-windows-with-azur...