Yes this feature is already scheduled to be added in the near future.
As for now, you can work around it by adding all the layouts you need for each monitor, and just use the ones that fit to each screen.
I actually wasn’t aware of the custom layouts that were available in the settings area before, I think I may actually like this more, I’ve been able to create the layouts I desire and keep other drop areas active which is an improvement over DDM in my opinion. I think your solution works better than DDM, the only thing that might be nice would be in the “custom layout manager” would be able to capture window targets to capture their window area into a custom region; Though, I was pretty easily able to use existing drop regions as reference to create the custom areas I wanted.
Any word if you’d be willing to implement this for the layout creation tool (the capture window target), I remember this was quite easy to do back in the VB6/VC++ days as MS had well documented callouts for it. I still see evidence of many apps using target capture today (screenshot tools and etc).