Hi, that is what the whole Cloud Design Library is about, check it out.
You need to create an account and set your own libraries that you will access from any Cwicly instal or share with any Cwicly user of your choice, even all of them if you please so…
As your message is from August, you might have seen this already,
unless you are talking about custom blocks you would have created and parts from templates (but these can be uploaded as designs).
Maybe I am missing your point or your feature is live now.