Hello John,
You have opened good topic here, and good questions inside.
Yes, the Meta Trader backtesting starts from the 100 bar.
So sometimes when you make a backtesting with FSB Pro, and it has in some of the indicators higher parameter than 100, you wont see a backtesting. It can not start. That is why you need to place manually a starting data(not using the whole period).
In EA Studio you have the option to choose if you want to use the 100 bar in during the backtesting or not.
![backtesting](https://eatradingacademy.com/wp-content/uploads/hm_bbpui/7932/qu4i715k14bh7i1vsjbyjwaebofw6uh1.jpg)