4 layer boards actually make it easier instead of more advanced in my opinion. You can have a dedicated ground and power plane which makes routing much simpler, and the fields are much easier to predict.

It's also just double the price, so I can get 4 layer boards for like $8 from JLC and it just makes everything much more easily.

You still do want to build up to it though, I made a macropad, then a keyboard, and then made this, so it's definitely not just an immediate jump, but I built those 2 projects within the span of a couple months!