Most of the later Binary
Switched Autotuners are, either Copied, or Reverse Engineered,
adaptations of the SEA1612B System.
Copied or reverse engineered might be a bit harsh..

The idea of a automatically driven LC tuner has been around a while,
with DC motors, servos, or steppers. Once you have the concept of a
variable L or C that's "remote controlled" using a binary switched array
is a pretty obvious thing to try. (e.g. I built a binary switched power
inductor for ballasting a tesla coil to replace the more traditional
sliding core inductor or variac with a cut core, and I doubt I was the
first to think about it.)

I think the subtle details in SEA's, SGC's, LDG's, or MFJ's tuners would
deal more with the means of detecting the mismatch and the actual tuning
algorithm. From that standpoint, the SGC and LDG tuners (which are the
two I'm most familiar with) are quite different. SGC uses a pi net, LDG
uses L net with cap switched between in or out. SGC and LDG use
different bridge and detector designs. I'm pretty sure, also, that the
actual tuning sequence is different, just based on the sounds they make.