Is Alt+SysRq+REISUB disabled in openSUSE?

I tried this key combination once when KDE5 plasmashell became out of control, CPU and HDD became overloaded and computer reacted slowly. But sadly it didn’t work and I only get a pile of KScreenshot windows after my computer back to life 10 minutes later.

It is disabled by default, yes.

You can enable it in YaST->Security and Users->Security Center and Hardening e.g.