Seems like an easy thing to implement, when we click delete you just stash the data somewhere but they are still there and then when someone wants to create a new collection with the same name (because the code depends on the name) it’s impossible because it will simply load the old one.
Delete should be “delete” not “hide” for all the obvious reasons.
Our specific case example is that we have 8 different sites with the same structure (for different languages) and some pages have the same code, now we exported and imported the collection but it didn’t keep the custom Field Key, instead it named the Field Key from Field Name - That’s a problem because it’s impossible to change Field Key (you lock it with message “The key is used in JavaScript code so it can’t be changed” even if I don’t use it in code atm).
I hope you understand the need for this and at least introduce a “remove permanently” button if you don’t want to change the stash functionality.