The law is very much on your side OP in terms of being recorded. Your neighbour is a data processor, so this means has has to be able to legally justify why he’s filming you and your property. You can request he blurs you out and request evidence, you can also request copies of recordings and deletion of any data regarding you or your family. By law he has to comply otherwise you can report it to the ICO.
You are not being unreasonable at all and I would write a letter to your neighbour with the legalities of it.
I also like the idea of lights and hedge style borders so consider those.
My neighbour, which we get in with sent me a letter about a year ago saying he intended to mount a high (roof level) CCTV camera in his back garden, pointed over my garden into our parking area for security (Despite there being no security issues) and I politely informed him that he wasn’t, as it was an invasion of privacy and pointed him toward the ICO website. He adjusted things to only overlook his garden and sent me proof, he’s now since removed the camera but the point is, if needs be you can make it very difficult for your neighbour so he/she needs to tread carefully and you both need to be reasonable and considerate.