I think I'm also in the same bucket as the original comment so can answer from my perspective. Coding is my hobby as well so spend pretty much most of my time

I think I'm also in the same bucket as the original comment so can answer from my perspective. Coding is my hobby as well so spend pretty much most of my time awake working on something whether it's for the company, freelance or personal projects that interest me. It's quite common that I'll discover something or gain relevant experience that I can reapply to projects in and outside of my 9-6. There's a list of things we want in JIRA that I'll work through and if someone says that something is important then I'll absolutely work on it but quite often I'll get random ideas of features or improvements and just go straight ahead working on it because I know it'll improve what we have or is valuable to the product. The project manager kind of hates me and asks how I decide what to work on and what my schedule looks like but it's mostly spur of the moment problems I'm excited to solve. Sure I'm able to do what I want but I still stay on course somewhat and it's all valuable. I've had a case where I did this when getting paid hourly. They told me it's not what they're paying me for so it probably only applies when it's on a salary or rev share basis :D