This one from Hotline Miami https://www.youtube.com/watch?v=SNE2oCZH_4k

The first two are kinda achievable with Nextcloud and davx. Not rock solid but for me it works well enough, the part about the map seems more tricky on first glance

Actua, plasma 5 was exactly as wonky with the panels already, especially when using different monitor setups in office and at home

Interesting, but what does this solve what Bookstack does not solve? I mean sure, it looks nice and hacky and all that. But if i am going to host some note thingy, https://www.bookstackapp.com/ is right there and apparently the dev nowadays lives from the thing (which is nice i guess). Not to belittle your project in anyway, even if something like your thing would exist exactly as that its still commendable but i am already running Bookstack and this seems to add anything to any use case i could think off.