Well... thank you all for your replies. I have tested several app in the meantime. Right now, I am giving ACDsee Studio and Exile Foto a try - either an my Mac and also my Windows machine. I am struggling on my Mac which is due to I am on M1 - and plugins are simply not working anymore in Affinity Photo (which is poor, but another topic).
What I see is that the search in Excire is incredible fast and a great DAM / photo organizer - but Excire doesn't recognize my Hasselblad raws neither on my Mac, nor an my Windows machine. ACDsee studio recognizes my Hasselblad raws on my Mac and can display a preview, recognizes these raws on Windows but cannot display a preview there. ACDsee can "look through" subfolders and bring a all previews (as Lightroom does is) but Excire can do this easily and damn' fast.
So - if you have no "exotic" raws (like me with Hasselblad) then you should give Excire Foto a try... as they have also a nice license policy which allows cross-installations on three devices.
Kind regards,
Robert