I do use mermaid quite a bit in markdown because it's documentation/code that can be updated, the idea tends to start in my notes as excalidraw, and eventually become a mermaid graph. I wouldn't say it's lacking anything. I have not tried it so I can't a valid opinion, but I am happy to give it a try and give some feedback. I do waste time converting. I see a couple of tools, do you recommend one in particular?

The only reason anyone uses mermaid is because it's low friction and most editors support it out of the box or through plugins.

But its layouting engine sucks and everything requires hacks and workarounds and configuration tweaks to display properly. Only the most trivial graphs render nicely on the first try.

All I really want to do is define how to actually lay out the blocks using a DSL so that they don't look like absolute shit. I hate drag and drop UIs and I hate mermaid. There's no decent code-first diagram building tool out there, let alone one that I can embed into my notes as easily as mermaid.