This is a great read for information on how to classify the scale of a project. Being able to compartmentalize the scope is good for determining when to execute and when to walk away.
I am currently working on a "main dish"[1] since it is for a smaller/niche market of people that modify their cars. I consider it the "side dish" to my day job, but with the goal of going full time with it if it takes off. If it takes off then I can start creating my own side dishes, complimentary products, to the main dish.
[1] https://azxiana.io/2020/04/21/translator-gateway-module-maki...