Very sorry, can not go into detail, but adding streaming support is more complicated, and deeper-level (core) changes in n8n are required.
Because of the amount of work and so time it would require from our side, to help you implement it (which is probably higher than doing it ourselves) we sadly not do help you. I started, however a while ago while I was traveling with the same idea. Sadly, I did not find enough time, but here is the wip code that is maybe helpful:
Good luck!