Yeah I once saw a great talk at a functional programming conference by a Scala compiler developer, making the point that programming language semantics should be specified at the AST level, with syntax entirely up to the user's whim.
I consider this to be both totally sensible and completely impractical :)
I tried using Idea for Scala 3 where indents are meaningful. I prefer size 4 tabs for indents. There were four knobs for adjusting indents and until I adjusted all of them the IDE was messing up my indents in subtle ways. If leading editors have trouble abstracting indentation from its textual representation I have zero hopes for them being able abstract even such simple element of AST as a block.
I think we might get it implemented some day but it's gonna be approached from the side of visual programming. Those systems just need to relax a bit and allow some structure inside their little rectangles. Then the internal structure will be able to easily have multiple views and editors.
I consider this to be both totally sensible and completely impractical :)