That looks very interesting. It has some commonality with a zettelkasten, specifically the crosslinking between blocks, and the idea that the blocks should or can be focused on a limited topic. The querying system is pretty cool (if I were setting it up I might have tried for a more SQL-like syntax). The zettelkasten system I set up in Leo is a little more hands-on for linking and such, and in using it I have found that having Leo's hierarchical tree in parallel with cross-links makes finding things much easier than just using cross-links. The combination of the two is synergistic, I've learned.
My system is built around four commands. It has a search app that loads into the Log frame, but even without it Leo's Nav pane search can find what you need pretty well. So basically with the four commands and a little discipline in how you use them you get a zettelkasten system, which has, as I said, the block + cross-link capability that logsec does.
I'll bet that the logsec people have worked out a lot of useful and interesting capabilities. Some of them could be recreated in Leo if anyone were interested, I'm sure. It might be useful to have a way for Leo to ingest and and convert logsec blocks for use in Leo.
I already have used Leo for daily work records and time sheet entries for certain projects, so that kind of use seems familiar.
Thanks for the post!