yes, started with Bo Laws, then his son Mike.
Then there was "Get em" - still around>
Now mike has licensed PMD to make the parts to go directly to the Carb building community , which, imho, is really where they belong.
As Dom well pointed out, they are a bit different .
For us, its been mostly dealing with pump shot timing because they get up on the boosters so freaking fast and you can thus be really overly rich on the hit .
Drivability wouldn't be a smooth as a dommy on the street.
We are using Dom's emulsion stack - as sent , rather then the one from Get em.
Afr's stay pretty flat throughout the run after the hit but, it took some experimentation with cams/shooters and will work a bit more on that this season, may try dropping to 30cc pumps from the 50cc as i think a shorter shot will clean up the 60ft afr faster- worth a shot - grin, pun.

PMD , as im told, has made further changes to the metering blocks but we haven't tested any and, honestly, thats something for someone like Dom more them me as he would know how those changes effect everything else , good or bad.
I do know several builders are excited about the metering blocks- couldn't begin to say why.
yes, , i think the Holley 3 barrel is what got Bo Laws to thinking about what could be done with twin blades .