They’re pretty much the same. Use docker documentation for learning, but actually use podman, because it’s nicer to use (doesn’t require root, easier to install on many Linux distributions).
How often does branchless programming actually matter in the day to day life of an average developer?
Barely never. When writing some code that really has to be high performance (i.e. where you know it slows down your program), it can help to think about if there are branches or jumps that you can potentially simplify or eliminate.
Of course some things are often branchless, for example GPU shaders, which need very high performance and which usually always do the same things. But that’s an exception.
Transferring the whole account after you die is what this post is about.