Here is the thing about tracking a second table:

Any successful player today, with today's conditions and higher house edges by rules like H17, quickly realizes that the "play all" approach of yesteryear, meaning playing through all counts, isn't going to cut it. Play all approach today requires a huge bet spread, aggressive bet ramp, and huge variance to get just a small edge.

So successful players adopt some version of escaping at lease some of the negative counts. Everything from bathroom breaks to pretend phone calls, just sitting out if the casino will allow it. For some players, myself included, negative counts is a trigger to find a new game.

So once a player adopts that mentality, exiting negative counts to find a new game, the next logical step is to start looking for that next game or opportunity even before that exit trigger has come. I mean if you are going to exit one game because the count is negative and join another table in progress without knowing any information about the count, then don't you think ANY information you have as to that second table and count is beneficial? This includes partial counts etc.

Anyone arguing partial counts provide no advantage should look into Standford Wong's (among others) extensive work on the subject. OR you can just troll and make statements you know nothing about.