I think I have a prototype you might be interested in, but I´d like to manage expectations first :)

  - It isn´t finished
  - The code is a mess (and not available online)
  - The UX clearly needs work 
  - etc. etc. :)

...but I started a thing with basically exactly the same gripes as you two. The only difference: Actually, I don't think collapsing JSON is nearly enough. I want pretty printers (like in GDB) I can rewrite on the fly.

So, if you're willing to plunge head-first into cold water without proper documentation, have a look at: https://run.pickaroon.app

Keep in mind that I wrote this to scratch my own itch and will change it further as time allows. On the upside, I've been using it for my own dives through logs quite successfully already.

I also started a manual-ish readme that also isn´t public yet. It's written in markdown, so I'll have to look into how easy I can throw it onto my server or not. I might just make a separate GitHub repo for the time being.

Edit: I went with the GitHub route. You can find the current iteration of the readme here: https://pickaroon.github.io/readme/