Any clamping is better than no clamping. But it's still amazing what you can do with just your body if you're willing.
Any time I start to get bent out of shape wishing I had the latest gadget and high-tech tool (and mine are even just hand tools) I keep reminding myself what our ancestors (and many even today) can create with very simple tools.
My parents saw one of these guys in Islamabad, Pakistan. It's still a way to get your work done in a large swath of the world without power or big machines
And the modern master of the ancient art of bowl turning on a foot-powered lathe, western style.