I'm general I feel icky about people telling employees how they should spend their free time.

I'm keeping an open mind, that's my initial reaction but if what follows is interesting then it has value nonetheless. In this case it's just 2 generalities that don't really help anyone, akin to me saying that to live a better life you should have a good work-life balance.

Everybody knows that, I'm not bringing anything that they can reflect about or act upon.

Yeah, I’m also quite conflicted on this. I don’t like the way the industry expects this to some extent. At the same time most of my learning comes from tinkering outside of work and some larger initiatives have started from me hacking around on parts of a work codebase or open source dependency on the weekend or after work.

A neat trick would be for a company to say “you work 40 hours but 5 of those can be anytime you want 24/7 - and you can tinker. That would be a perk. some people can just do the normal 5 days but others might do stuff at the weekend because it is when they want to do it. I believe tinkering is essential for productivity not Jirafying evey minute of paid time. Software is non-linear. A tinker could lead to an entire team-quarter of work saved.

The Ayns will say do those 5 in addition you lazy bastard to which I say OK then I will do them for my own IP/ideas.

Advice on being a better professional from a colleague and an employer dictating my free time usage are entirely different things. This thread is very clearly about the former.