For years I worked at a large company with so many blockers for everything that I always worked like this all the time - have 5 projects so when one becomes blocked for external deps, you have one to pull out and work on. There is a context switch (which lead me to context preservation habits like checking everything I write into git; using tmux so that the context is sitting around in the bash history of the shell where I was working, that sort of thing; lots of org files and Mac stickies with TODOs etc).