You’re right, just position high as possible without colliding with XY motion. For me that ended up being ~35mm from top of top extrusion to top of Z Belt Holder, see model in Fusion if possible. Fortunately there’s a wide margin available for where you position height of the top Z belt holder. At least that was true for my build… Given the overall thickness of the build plate assembly , and hotend/nozzle am using.
Hopefully following screenshot from this clip (part of Klipper Heightmap Calibration ) helps illustrate…
