The small scale is an artifact of X11 rendering. I've found that, at least on KDE, switching to Wayland and then going to display settings and selecting under "Legacy X11 applications" the setting "Scaled by the system" will make X11 apps like Spotify render much better when using display scaling. Alternatively, using chromium or edge and "installing" spotify.com as an "app" uses browser rendering that is much nicer to view and use. The web client also doesn't have that annoying "beep" when changing songs that I seem to experience on OpenSUSE when using the X11 client. Hope this helps a little.