Writing them, on paper, has been very helpful. The act of writing, the pace of it, the composition of what I'm going to write, combine to help make the information more durable in my head some how. I've got a ReMarkable 2 notebook which gives me infinite pages which is kind of neat, but I still like paper notebooks.
They have saved me a couple of times and made me more productive. Since I often have a number of projects in parallel so that I can pick up one when the current one hits a stall (like waiting for parts, or needing different equipment), and when I come back to a project I've organized my notebook so that I can re-create my mental map from where I left off.
And in one instance it torpedoed a vendor who tried to patent an idea that we had reached out to them for help in developing.