Been using SPAD for years with my Logitech FIPs and panels and it works well. It does not really install anything that should trash something — it uses the Logitech FIP panel drivers itself.
Given that you removed SPAD and are still having the problem, it is likely something else. What software are you using to select the panels you want to display now that you removed SPAD? What plane are you trying to use them with? Some of them really only work with SPAD or something like it.
That all said, SPAD is complicated and you need to spend some time learning it. Highly recommend some of their videos on YouTube.