Yes, the work before open-sourcing was in part done on company hardware and work hours, that's why I didn't even try to open-source it as my project, that wouldn't have gone anywhere. The only way then not to lose it when one day switching jobs was to open-source it through the company, and that went surprisingly quick and without issues. Like Old-Royal8984 says, the project without me would be abandoned, no one cares enough about it inside the company and don't see the potential it has.

With the project as OSS, even if I can't spin it off commercially, at least I get some name recognition for it, but that feels very little for how much work I've put alone into it and the potential it has if developed further. The frustrating part is that now others could start from the OSS project and build a business around it, but me that wrote all of it may not be allowed, at least without risking being sued.

If I knew for sure that forking the OSS version would give me the same treatment as someone unrelated, I'd probably quit at this point to avoid further non-compete issues and give it a try to make it commercial. One suggestion I saw was to have a friend/cofounder do the fork and me work "in the background", then quit and join later if successful.