Thank you, Emma. you helped a lot.

"Have you thought about what I've said? " sounds more natural.

Have you thought any more of what I have said. Yes it does mean - have you thought about what I have said. Or another way to say it is.. have you thought anymore about what I said/ Have you had any further thoughts about what I said earlier. They have already had a conversation, and an opinion or point has been made, they are then asking... Have you thought any more about what I said/ have you thought again/ had another think about what I said from a previous conversation. Does that help?

It sounds a little odd: "Have you further considered what I said?" "Have you been considering what I said?" Have you further thought about what I said? Have you been thinking about what I said?