The alt gr + ß is probably the same for nordic keyboards, the one below A. It’s <>\ for me, but afaik both < and > are also individual keys on a US keyboard. And then there’s ~. But I guess you get used to dead keys.

Shift+7 feels wrong for some reason, so I currently tend to just send my pinky on a kamikaze mission towards the numpad hoping I hit /. Sometimes I hit numlock, sometimes I hit *.
Even if I made a compose key “shortcut” via ~/.XCompose it’d still be more work than what I’m doing already.

Macro pad could be a solution, I have considered it beforehand for other purposes tbh

If you know what a nordic keyboard layout looks like, you’d probably prefer backslash. Since I moved to Linux a year ago I’ve been struggling to find the easiest way to forward slash. Shift + 7? Or numpad / with my right pinky?