> This MSC is meant primarily for bridges to signal to clients which "richer features" are not supported, allowing clients to hide or prioritize UI elements so their users do not unwittingly send events that would be bridged either badly or not at all.
Ability to disable richer features per room or space. #836 github 
> In future, once matrix-org/matrix-spec-proposals#1767 lands, we could also enforce more of these by blocking the event types using PLs (e.g. blocking files/images/edits/replies/reactions).
MSC1767: Extensible event types & fallback in Matrix (v2) #1767 github
This in turn would make IRC bridging way nicer, as the bridge could configure Portal rooms by default to have no edits/replies etc, and so eliminate the hate that Matrix gets for that impedance mismatch – while still letting room admins loosen the restriction if they care.
~
Howard Stearns via discord thinks there's a natural desire to reach out and touch what you can see, and it's slightly disappointing to follow up on the delight of opening a portal with a limitation of not being able to touch. […] – do we really need to?
DOT FROM two-level-diagram
maintains nesting through the availability of open doors that permit access to deeper rooms. Explicitly the outermost door leads outside.
Picture for a moment that the Square-Brackets of the List are Walls.
What Ward did is thinking anew about how we might make a Link. That link is a link that has a lot of respect for people because it opens doors instead of putting up walls.
Divergent paths are Choices of which door to go throught. Computation implemented with the room model involves closing axiomatically specified doors. (Bricken, Iconic Arithmetic. Volume III: The Structure of Imaginary And Infinite Forms, p. 355–356)