I remember catching a decent amount of shiny beldum in a previous event outbreak (one that had beldum in blueberry academy and hisuian sliggoo in Kitakami). I remember struggling for some beldum but catching a couple rather easily without weakening them (I used premier and luxury balls), and this was on a file that had significantly less captured Pokemon than my main file. However, today, it took a bunch of balls to catch a shiny beldum I found in my main file (I caught it by surprising it from behind, but I hadn't for the beldum back then). Neither times had used catching power.
So, was I just getting lucky with the beldum, or where there actually increased catching odds for the outbreak?