I use a level 2 count that does not include aces in the base count. For betting the aces (extra aces that is) increase your bet count by +1 for each extra ace. For instance if the true count is +2 with 1/2 deck played in single deck, if you have seen 2 aces the bet count is 2 units. If you have seen only one ace the bet count is 3 units. If you have three aces out, the bet count is 1 unit. (I'm sure you get the idea).
For insurance purposes, the ace acts only as a non ten value card. If I am on the index for insurance, an extra ace calls for passing on insurance; a deficit of an ace calls for taking insurance.
For playing decisions, it can be the decision maker for doubling 10 vs 10 or 9 vs 7 or 2. It really doesn't factor into my 11 vs 10 decisions as it doesn't impact my basic count.
"Whats the best way to use side count of aces? For insurance only to get an accurae count of the tens that still are in the deck?"
It can help in some cases for that, yes. The main reason to side count or side track Aces is for betting purposes.
"Do most pros count aces?"
It seems less and less people side Aces as time goes by. The Hi Opt II by Ph.D. Lance Humble is a great example of the Ace side count. Ustons APC perfected tracking Aces per quarter deck. The new "pros" will tell you that it is too difficult for what you will gain from it. If you can't do it, then it makes no sense, but if you can, it will give you a better edge. I think most of the real pros use Hi Opt II but will not tell you they do. It's an anti-Canadian conspiracy (Humble is Canadian), similar to the Avro Arrow scam....grin
errors in how many decks have been played count double as this efffects both your true count divisor and the accuaracy of your quarters versus aces count. Most side count advocates also make several Ooops, I left the corelation coefficient out of my math toolbox today type mistakes where they relate how an extra or deficient ace is worth so much compared to the 10s in an isolated manner. What matters is purely how the combination of the side count for aces, which is equal to counting every non ace as +1/12 (for a single level count) and -1 for every ace out of play, correlates to the effects of removal for the overall game. This combination of counts is a bit weaker than most assume; the errors in decks played brings both running count and true count divisor errors. Your overall performance is cut further!