Taming grey curly hair

[TheGirlOnTheLanding]

I know there's been a few threads about letting the natural grey through but all the ones I've read are about how best to go from dyeing to natural. I've never dyed my hair (late 40s) but have recently started to have more and more silvery hairs so imminently have to decide whether to leave it to turn naturally or dye it to hide it. I don't mind the colour of the silvery bits so far and so am inclined just to let it go grey naturally, but I hate the coarse, curly texture - as the rest of my hair is very dark and straight they literally stick out at angles near the parting until they're long enough to get the straighteners onto them - not a good look. Any tips for taming them, products that will smooth and flatten them? Serum makes my hair go limp so would avoid that if poss.