Hey there!
I do think that Joomla Modules is one of the strongest point in terms of templating. But the way we visualize our data does slow people down.
We can just show the template structure. Draw modules area outline like "tp=1" on our site. By this, user can imagine easily how would it looks like without too many save
Also, we can show available modules that are not activated or used at sidebar
Show enabled & disabled modules at each module area
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Also, I'm suggesting to use Bootstrap Modal when we are creating a new module or edit existing module. By that, we will minimize our time to manage module
p/s: Sorry for bad sketch.