I ended up moving to kdenlive that offers a “paste effects” option that works on multiple clips. Hopefully something similar is implemented at some point in shotcut as well (or make “fade in” work when setting filters for the whole track, as mentioned earlier). I see the paste filters to multiple option has already been requested here, though I don’t see it on the roadmap unfortunately EDIT it’s the “multi-select support for Filters” entry according to this comment. Good to see that it’s planned.
I’ll definitely be keeping an eye on Shotcut’s development, as there are a lot of aspects I enjoy.