I use these as well, but maybe something I didn't articulate well is that it's often useful to remember where I've been. One thing that I haven't played with in VS Code but that bites me a lot (and sorry, I don't know the proper name for this setting/feature) is that often when you're navigating you're doing so in the same vs code tab. If I remember to double-click the tab it'll hang around, but that's a pretty janky workflow, and I don't ALWAYS want to do that. Ctrl+- works if I hop into a method/function and want to look at it briefly and hop out, but I find if I go more than a couple levels deep it would be nice to mark certain areas as I go so I can easily get back to them.
Sometimes I do this by just adding a comment, and now that file will at least show up in version control as changed and I can get back to it if I need to, but that's also a little bit janky and I have to be careful I don't leave that cruft around on accident when I commit.
I'm trying out a bookmark extension in VS code and we'll see how it goes, I'm already a little bit annoyed by it in that it doesn't seem to let me organize the bookmarks in any way, so it might be somewhat useful for temporary spelunking, but I won't for example be able to save these bookmarks to refer to them later, which seems like it could be useful.
Sourcegraph has this concept of "Notebooks" which allows you to add files and intermix markdown, which feels like a pretty cool idea, and if I'm just reading code in Sourcegraph it's great, but when I'm in my code editor and making changes I don't want to bounce over to another tool. Maybe it's as simple as keeping some sort of Markdown file open that I write into and then add links to file line numbers as I go, I haven't tried that but I suppose it wouldn't be the worst, and allows me to organize the links in any fashion I see fit.