Please, don't phase out "Multi-Window Source and Destination" somewhere down the road (DOpus 13.5, 14 or so...)
I know it's still here, but i also know where something like "People tended to find this concept confusing, or simply didn't use it, so it's now off by default." can lead. 
No plans to remove it entirely. 
But I know what you mean. As soon as Chrome makes something optional you know it’s gonna be gone in 3 months.
Can we pretend I'm a very uninformed and not up to speed with lingo and what not, and explain what you mean by multi-window source and destination. I mean, I understand the words, but would like to know what it actually means.
And I hate this crap that chrome has turned into. Every damn day it looks more and more "appleish" and it just sucks. it eats resources and is driving me crazy every time it updates the damn thing gets worse. Just had to rant after reading Leo's blurb about chrome.
You open two "listers" at minimum with different folders in them, and then choose one to be the destination. Now you go to the source and select files/folders and then click buttons (or hotkeys) to copy or move files/folders. These files/folders will go to that destination folder. The thing is that you don't even need to see that "destination lister" window and it can be minimized or even hidden under something. Quality of life feature.
idk what is so complicated about it to not use it. 
Without it you would need to use copy/paste or cut/paste combo, or maybe "copy to/move to" DOpus features where you can also select destination with a lot of clicks, or even drag them manually 
to some random places of the DOpus (as there are many places in DOpus which can be used as destination)... or type thingies in the command line like a true hacker. 
lol "like a true hacker": Got me laughing. I guess I'm not enough of a power user to have ever sat down and read the manual on what the whole "Source/Destination" deal was with DOpus. I mean I have seen it all over, but never thought I had any use or need for it? Now I want to .. like... learn how to use this program. Thank you for explaining and not being a dick about it! Happy Holidays 
You can also use a dual file display, which isn't affected by the change. Those always have source/destination sides (e.g. so you can move files from the left folder to the right folder).
Doing it between two completely separate single-display windows is now off by default, since people clicking the "Copy Files" button without understanding what it would do in that situation might copy them to an unexpected place (whatever another window was showing) without realising they'd even done it. But it can be a useful feature for people that learn about it.
How do you set the source and destination in a Multi-Window Source and Destination configuration? TIA
Oh I didn't know about this feature either!
I'll probably never use it as I'm too used to a single window with dual pane and tabs.
Interestingly, this looks to be a continuation of the SRCE / DEST / OFF mechanics introduced in the multi-window Opus 5 on the Amiga, so this feature is in the DNA of the Opus, and even though in modern days people don't use it as much it would be akin to amputation to remove it
The manual explains it if you're still not sure what it all means.
Opus 12: https://www.gpsoft.com.au/help/opus12/index.html#!Documents/Source_and_Destination.htm
Multiple Single display Listers???
I was not aware of this feature. To me this method of copy/paste feels intuitive and confusing. However some people might have found it useful.
