Hi Christian,
Although I think PREMIS metadata is a useful standard to implement, I often think that it is overstressed in terms of priorities for managing digital collections. The most useful part about PREMIS to me is the events model, but that type of metadata isn't listed until Level 4 of the NDSA Levels of Preservation.
https://ndsa.org/publications/levels-of-digital-preservation/
In my experience I have found it more useful to first invest in other practices that are more useful for day-to-day operations, like creating file inventories and procedures for monitoring file integrity. At NYPL, we have some basic preservation event metadata sitting in various logs. These have been piecemeal and their quality has varied depending on the staff involved at the time of the effort. We haven't made an effort to combine these logs and transform them into a more official standard, primarily because it's a lower priority task than some of our other digital collection management processes.
If you already have those other practices covered, it's great to dig into PREMIS and event logging. Even then, at NYPL we're in the process of implementing a preservation platform because event logging is a non-trivial problem to solve.
-Nick