Comment # 5 on bug 1112824 from Robert Munteanu

I installed the following packages and the responsiveness has greatly improved:

gjs-1.54.2-163.1.x86_64.rpm
gnome-shell-3.30.1-393.1.x86_64.rpm
gnome-shell-browser-plugin-3.30.1-393.1.x86_64.rpm
gnome-shell-calendar-3.30.1-393.1.x86_64.rpm
gnome-shell-devel-3.30.1-393.1.x86_64.rpm
gnome-shell-lang-3.30.1-393.1.noarch.rpm
libgjs0-1.54.2-163.1.x86_64.rpm

The CPU spikes are gone from the gnome-shell process as monitored via

  top -p $(pidof gnome-shell| tr ' ' ',') .

I'm intentionally not removing the needinfo flag as my laptop did not have
smooth animations before the update either so I'm not sure if the problem is
entirely gone.