I use some workflows like modules so can end up with heavy nesting. No problems so far.
E.g. I have a workflow that handles a request and then calls another workflow that works with confluence. The confluence workflow then calls another workflow to update a page, inside that workflow if the page doesn’t exist it calls another workflow to create the page. So that’s 4 levels
I also do this for larger workflows or workflows that handle more data, I like using a lego style approach to things where I can just have a bunch of helpers I can plug in depending on what I need to do.