I was trying to find the original diagram that I worked from and didn't, and I didn't download it either which is annoying. However, I did find another reference page which shows clearly what I did, as I do have text notes to tell me what connections to make. I should have checked those wiring diagrams properly against what I used.
https://www.stewmac.com/video-and-ideas/online-resources/learn-about-guitar-pickups-and-electronics-and-wiring/blend-pot-wiring/
My notes definitely say to connect the crossovered non-hot ends to ground. If you compare that to a V/V/T setup, the pickups are loaded exactly the same - at one end of travel the pickup hot goes to ground, from the halfway point to the opposite end the pickup hot is straight to volume hot, and in between fully off and the centre point there is a varying amount of resistance.
https://www.stewmac.com/video-and-ideas/online-resources/learn-about-guitar-pickups-and-electronics-and-wiring/learn-about-wiring-stewmac-pickups/stewmac-bass-pickup-wiring-diagrams/ - second diagram