The Official Spindle of Onefinity CNC by @Redlinecnc
I have the 65mm spindle and the Gen 2 dust boot hits every time I lower the spindle…does anybody else have this issue?
try lowering your spindle in the holder and slide the dust boot down
I had the same issue. I found that when I attached the dust boot I had allowed the end with vacuum hose to lower a couple of mm. That caused it too hit the z axis support. I readjusted the boot and now it clears the support but just barely.
I tried adjusting it every way possible and it hit everytime. Onefinity support said there’s an updated bracket that solves this problem and they’ve shipped it to me. Hopefully it solves this. Thanks for the responses! 
I also had the same but mine was hitting on the 80mm spindle and boot. The new bracket has less material between the linear rails and the spindle.