pendrive clone impossible ?

[Anatoly]

On Sun, 1 Dec 2019 08:28:01 +0100
Gary Jennejohn <gljennjohn at gmail.com> wrote:

> The geom code protects certain parts of the data area on the
> drive, in particular GPT/MBR areas, unless ``sysctl
> kern.geom.debugflags=16'' is run beforehand.  One can see this in
> many places in the geom code.
> 
> I always set this sysctl when I know I'm going to overwrite the
> first sectors of a drive.
> 
Interesting, but I've succefully overwrited MBR many times
on FreeBSD 5.x-11.x without setting this sysctl.
I've learned about this sysctl when I first time failed to overwrite bsd
label inside MBR slice under FreeBSD 7.1 with dd (but not MBR). There
was explicit write error, not just silent succeful write to nowhere. I
may be wrong, but as I remember, I newer got this trouble again
starting from 10.x.
Is there something new on 12.x?