To bulk copy and paste put elements in a View element (a.k. Group) and copy and paste the whole group
I'm hoping as i play around with dropsource i will be able to share some of my own tips and tricks here.
Since Dropsource is still growing and may not have all the features and functionalities we need sometimes you've got to achieve your aim with some workarounds here and there.
One of my current frustration with dropsource is the inability to select multiple elements and copy and paste them.
e.g. if you want to create a bottom navigation bar which will be present in multiple pages, you don't want to redo them all over again on each page.
The trick here is to use grouping (bubblers are familiar with this concept very well). There are several advantages of using grouping, e.g. for laying out your pages, but here the focus is just to use grouping to aid copying and pasting multiple elements.
When multiple elements are in a view (Group), it allow you to quickly just copy and paste the group to the same page or another page.
The warning here is that since currently you can't undo/redo if you mistakenly delete a group it's gone forever. It has happened to me where after designing a page for about 3 days, while i was trying to delete an element i had mistakenly selected the whole group and when i hit the delete i lost all the contents of my page (i normally have my whole page in a view).