On average I also spend a lot of time creating new puzzle caches.
The great thing about puzzle caches is that everyone can have/create their own kind of puzzles.
I took a quick look at your mentioned puzzles (Nice puzzles by the way) and although the genre is different, my process is not that different.
Idea, this usually comes naturally
Creating/building the puzzle content
Testing
Changing after testing
I then let my wife or one of my kids solve the puzzle (I give them only hint to speed things up, not the answers)
Changing after testing
Hiding
writing the cahce page (always takes more time than expected)
Release, always pass on a lot of information to the reviewer otherwise you will still get questions ...
Wait for the FTS and FTF
So, it's not insane. I think for me its always days work rather than hours...
For my most recent one Mars 2020: At least a month, but mostly in the weekends and after working hours...