The curly redwood is a soft wood. I have tons of it, and from personal experience, yes, it would benefit from being stabilized. I'm actually buying a stabilizing system because of how much of this I have. I've turned a bowl with it, the only way I could finish it was to soak it in poly. I gave my neighbor some and he had a hard time doing a pen with it until it soaked it in CA. It makes awesome bowls, bottle stoppers, pens and so on. But it is a soft wood prone to tear out. At least the curly redwood I have is.
From my experience, it depends on the piece. I have turned some redwood or redwood burl for pens that had no need to be stabilized. And I've turned some that definitely needed to be stabilized and limped along the way with CA soaking. I'm set up to stabilize, so these days I err on the side of stabilizing something questionable, rather than turning it and going through a ton of CA to harden it or going through the time of collecting things to be stabilized and then sending it out to someone and waiting to get it back.
