Everyone that is lucky enough to get a good p3a says 'calibrate again', but those of us that have gotten units from the suspected bad batch will attest that there is something defective with this batch.
I returned mine and have never seen a calibration error since.
This looks to be it:
https://www.amazon.com/Aboom-Extension-Bracket-Extended-Controller/dp/B01HOX1XV0/ref=pd_sbs_63_1?_encoding=UTF8&pd_rd_i=B01HOX1XV0&pd_rd_r=ZBM12YA643XFYN5R5E35&pd_rd_w=rHrT3&pd_rd_wg=wP7IA&psc=1&refRID=ZBM12YA643XFYN5R5E35
Although instincts might lead you to believe the Prop Mounts are a point of failure, we are seeing that the mounting system is actually very reliable.
A lot more reliable than the average operator....
I love the way they condescendingly write "those marks are called scratch marks"... LOL
In these parts, this is akin to calling you an idiot.
I think they are telling you this file is closed.
Fishie
The photos look like more like brass than copper. Or is it just your camera?
Too bad you didn't do a comprehensive review and comparison to their Al ones to see if copper's lower electrical resistance actually has any measurable difference. I doubt it.
Buddy is 100% right on this one! Review and re-review these elevations and you will be fine. Ignore them and plan on getting to know the UPS guy real good for all the parts you will ordering.