Been catching up on older @waitingforreview episodes and in one of them @daniel made a great point about side projects: one of the resources to manage is your motivation.
Essentially, it’s ok to deviate from "typical" standards you'd normally (have to) follow - maybe you can't be bothered with tests, maybe you want to try a brand new thing - because your motivation to do the thing is an important part of it.
Don't feel guilty for doing it in ways that are fun. Hold it whichever way you like.