I have spent a fair amount of time thinking about this. Fundamentally in order to discuss improvements, it's necessary to identify the sources of pain. The largest problem (and/or existential threat) I can see with LW is its stagnation/decline, both in content, and in new insights generated here.

Charitably, I suspect LW was built with the assumption that it would always have great content coming in, so the target and focus of most design decisions, policies, implied norms, and ad hoc decisions (let's call all these 'constraints') was to restrict bad content. Even its name can be thought to point to this principle, but the infamous 'Well kept gardens' post is also a good pointer. Unfortunately, the side effects of these constraints plus the community as shaped these constraints has been to push out most of the best authors in the community, including the earliest active members, who have spiraled in many different directions, while being nominally still affiliated with LW and/or it's community. As a result, LW itself is a shadow of its former self. Currently, the community is in a process of concentrating in other venues, with Slate Star Codex probably having more comments/day than LW itself, and SSC is not the only alternate venue.

With the above problem statement in mind, the best ROI for a developer wanting to improve the experience of the broader LW community I can find, is to set up a Hacker News clone (e.g. an instance of telesc.pe) aimed at the issues the LW community cares about.

Having a central location that aggregates worthy content from LW, SSC, OB, the MIRI blog, most other rationlist-sphere blogs, plus an equal amount of content from the rest of the web that is of rationalist interest, collectively filtered by the community, would make my experience of the LW-sphere much, much better, and I suspect I am pretty typical in this regard.

The aggregator not being under MIRI/LW control would probably be a net positive, given the history of management of LW itself. The point would not be to replace the things LW does well (giving a venue for people to post relevant material), but to replace the things it does not do well (aggregating the wider rationality community, filtering quality in a quasi-democratic way)

The major problem for such an aggregator would of course be lack of adoption, so I would like to hear from other LW members if such a move would interest them. I am committing to set this up if convinced that there is indeed enough interest. I have provisionally bought distributedconspiracy.com for this purpose.