Nice, I'm just starting to cross breed flowers, have gotten pink roses but no black ones yet. I did read that the the Friday->Saturday transition is the best for cross breeding, but wasn't sure if that was roses or all flowers (it was a video on how to breed gold roses).
Saw this site which details all the islands. For 5% I sure get trash island a lot.
http://wuffs.org/acnh/mysterytour.html
Also details on balloon spawning, I'll be glad when the bunny day balloons are gone!
https://www.reddit.com/r/ac_newhoriz..._150_balloons/
BTW the bunny day balloons have a louder and higher pitched whooshing noise associated with them.