Hi Jim,
Felgo extends Qt, so it is possible to build Felgo apps for all supported Qt platforms and features, which also includes Qt commercial. Due to maintenance advantages, the Felgo SDK uses custom Build Kits with a stable Qt version. The pre-built Felgo libraries available with the installer cover all major Desktop and mobile platforms (Win, macOS, Linux, Android, iOS). Felgo builds for other compatible Qt platforms (e.g. embedded systems like Raspberry Pi or i.MX6) or builds for different or custom Qt versions, are available with Felgo Enterprise or a support package.
If the qt version is compatible, we can also instruct you how to copy over relevant files from the Felgo SDK to a custom Qt installation. Just get in touch at support@felgo.com to clear the details. Please also let us know which platform / Qt version you want to support exactly.
Best,
Günther from Felgo