on desktop, using it under LGPL is not really an issue, so you don't have to go for commercial (where I'd agree the value proposition isn't there very often sadly)
Thank you very much! Without your comment I would have dismissed this option.
Dynamically linking against Qt libraries means that the copyleft is not viral, and your software does not need to be licensed under any GPL-family license.
What you probably are really asking is do I need to release the source code? As long as you are not statically linking an LGPL library... which last I checked a few years ago... mobile required that but not desktop.
Just have the separate qt libraries in the same directory and I believe you should be good.