Thanks for sharing excalidraw as well. That looks great.
That said, in real-world video calls I've found that having the whiteboard be collaborative is essential. Being able to see a colleague's mouse cursor as they're asking a question out loud, or someone else being able to draw a little alternate part of the diagram right there -- this stuff can make technical planning discussions way more productive.
We started with https://miro.com, and then moved to https://beta.plectica.com for our diagrams / whiteboarding. Both are pretty great...
I prefer collaborative editing for meetings as well, but my use case for this is more academic. I'm using it as a stand-in for a board that I'd usually use at the front of the classroom to make a quick diagrams or notes during a lecture, so collaboration isn't especially important to me. I simply wanted something clean and distraction-free.
It'd be sweet to add collaboration to this, but that's obviously an order of magnitude more complicated than what I've built. Perhaps I'll get around to it eventually.
With Miro you basically just get bulleted text lists, which is fine but only gets you so far.
With Plectica you can nest cards inside of cards, which means you can drag drop to re-order, give nested cards their own tags, etc.
So for things like modeling a db schema (lists of columns in tables, each column with its own attributes) or planning user stories (lists of tasks to support use cases, each task with its own parameters etc), Plectica is just really flexible / extensible.
I know you can use Ctrl-Z but if I want to change a box I made early on then this doesn't work because I'd have to basically start over from scratch.
I don't generally love the idea of taking over right click behavior, but I've pushed out a patch to allow removing elements using right click. This is an admittedly poor solution (especially for lines, as they are very small click targets). Hopefully I'll have a chance to develop a more robust way to delete elements such as the box method that you described.
edit: author just changed it to shift-click
Anyone have any suggestions?