I purchased VirtualProg when cheaper as an experiment and to support a new developer. But it really is not yet as stable and feature rich as UTM or VirtualBuddy. Both of them are free or optional payment.It appears to be an intriguing product, and I was contemplating replacing VMware Fusion with it to opt for a simpler and more lightweight solution. While I'm willing to pay $10 for it, I just checked the App Store and discovered that it's now priced at $22.99. Considering that I can utilize a much more feature-rich product like VMware Fusion for free, I find the current price to be excessive.
I am happy with VMware Fusion for most things. To my mind the only reason to use anything else is for macOS VMs on Apple silicon host - for these VirtualBuddy or UTM seem to be the way to go.