Interested in checking out non-D&D fantasy "old school" ttrpgs

[Voadam]

Clockwork and Chivalry sounds the most appealing of the spinoffs if going by name. Do you have any experience with that one?

Not really. There are some decent reviews for the 2nd edition though. I got it because the setting was fairly intriguing, English Civil War with Cromwell, Puritans, blackpowder era, with fantasy elements including alchemy, witchcraft, and clockworks. A bit Warhammer feel but with no nonhumans or big overarching Chaos. Clockwork & Cthulhu adds full on Mythos into the same alt 17th century setting. Also has a big chunky campaign adventure.