Is that any different from normal? In my experience, if you're shipping a product on a Linux-based desktop, usually you target a specific set of distributions, i.e. the default configuration of the last few LTS versions of RHEL or Ubuntu or whatever, which at least for those examples all happen to be GNOME based. Customers who come with some weird hacked-up distribution would be on their own for support anyway, they can try it but there's no guarantee it will work. If KDE (or something else) really is doing something different here then you would have had to extend the same amount of effort as you did previously.