Hello Daniel,
EA Studio is just amazing. When you work with it for a longer time you will realize how good EAs you can create.
I am not sure if the auto lot is possible, but that is not really necessary because the idea here is to trade with many EAs in one account. Like you did a good one already. When you build few more like this(for example 10) you will be able to trade them simultaneously. This is where the beauty comes. You will have a portfolio, and you will diversify your risk. Let’s say you want to trade with a complete lot. You can trade with 0.1 lots each strategy.
If your account goes on a profit, you can either increase the lots to 0.11 or you can add another EA which for me is the better way.
Hope that gives you a better idea.
Cheers,