I Think I’ll print this one Printables
and use the probe on the screw like you did 
I really wish there was a tramming adjustment built into the LR3 core though… adjusting this seems a bit sketchy…
If I can measure the deviation, maybe I can re-print customized brackets to account for it?
Another question: when I measure the distance between the arm extremity and table, how do I know it’s not the table leaning on one side?
Wouldn’t it be better to use a digital level?