If you wanted something lighter than Mint you could also try Lubuntu or Linux Lite, all three are good options for older hardware though 👍🏻 in my experience something usually breaks with Manjaro after a while... might just be me though 😂 your personal set-up sounds solid and practical 👌🏼
Discussion
The more comfortable I get with customizing Debian the more I view the features in Mint as obstacles. I find Debian with LXQt is light enough for most of my old laptops. I've even got a Toshiba Satellite from 2009 running LXQt with i3wm. It can't do everyting, but it's impressive.
It's amazing what a bit of linux bootstrapping can do to old hardware 😎 i think that if more people realised this, and how user friendly Linux actually is these days, we would be able to massively reduce e-waste