when to introduce pillow & duvet?

my son is almost 1 (5th feb) and for the last month or two he's woke up almost every night and it's not just for milk, we did milk the first month he did it and then put him back into his cot but that stopped working as soon as he would touch his cot he would wake up crying and stand in his cot untill o would pick him u and put him into bed with me. since then he's been in my bed almost every night in bed with me on my pillow and in duvet with my arm around him too.

we bought him a pillow and duvet and have tried it once for his nap today and he slept 2 hours undisturbed in his cot with it and didn't even want to wake up after that🤣. but i'm not sure when to properly introduce it to him, like through the whole night. i'm going to keep using it for nap times but i'm not sure about night time? he hates being in his cot now but he loves it in my bed but he takes up so much room cause he will somehow wriggle his way ontop of my whole pillow so me and my partner are crushed together, hes also quite annoying to sleep with since he has a thing with pulling and trying to eat hair all the time any chance he gets 🥲

when did you introduce pillows and/or duvets to your little ones? and what were your experiences or when did you feel ready / baby show signs they was ready?