I couldn’t agree more, but it did not work for me on Plasma. 
I got the idea for the solarr-pip install from a Dev, Hence the warning “YMMV“
I have not included the pip install method intentionally might scare off the OP.
This method has been successfully used by users with Solaar installed via pip, which can sometimes have different autostart behavior compared to packages installed from the system’s package manager.
But if your method works for the OP on Solarr from AUR then I might change mine as well.