I think there is no problem using his hands at this age. I would keep giving him a fork at meal times and maybe stab one piece of food for him and just leave it there as an option for him to pick up and eat from, or ask him 'do you want to stab with the fork?' or something like that but only follow it up if he said yes. I help DS stab when he wants my help, he will indicate either that he wants me to load the fork or he wants hand over hand help, he also makes it clear when he doesn't want help and will stab on his own or when he doesn't want to use the fork at all. I also ask and help with hand over hand cutting up with the knife and fork.
I think it's pointless insisting or strongly encouraging fork use because with each development they seem to want to re-explore the things they already knew, like textures and squishing. I also think they sway between their desire for independence and their desire to master new skills, sometimes using fingers is more independent (could say more 'grown up') than using a fork because the fork might need help loading.
That's my thoughts x
