I’ve had similar problems with a 3’ cable between cells. It is near impossible to get voltage drop near zero.
I guess you could only check resting volts. Ignore cell volts under load.
On the bolt battery, I think I ran a heavy balance lead from both points. Don’t remember the results.
Worst that could happen is it burns off it the power cable fails. Maybe fuse them to protect the wire or use a fuse-able link.