Nice setup. For the X100 series, I’d be hard pressed to decide between the Nisi and the Squarehood offering. The Nisi wins for an all in one solution that keeps the camera profile as small as possible, so I’d probably lean that way as well.
Not going to help, but Matt and Steve, the A7C is a fantastic camera for both a compact high quality system or for grandkid chasing.
AFC focusing is so good at both tracking or composing - point at subject, half press, then recompose to your hearts content and the focus will follow.