Hi @NiceThings, welcome to the Community!
Please note the pre-cueing of the Looper and Sampler outputs is not currently supported on any hardware. There is an existing suggestion topic for this that you can upvote though: Looper & Sampler Pre-Cueing & Audio Routing Options
This is correct. You cannot currently add your own loops to the Looper or customize the existing packs. Please note that the functionality of the Looper is much more complicated than it seems under the hood. So, while supporting custom loops seems trivial on the surface this is much more complex to implement effectively. There is also an existing suggestion topic for this that you can upvote: Custom Looper packs
I hope that helps!
