Glad to hear you liked the video.
Yes, many people asked for the % size lots, but there are many concerns about it. If you trade many EAs in the account, each trade will open different sizes, and it will be hard to compare the EAs and decide which one had the best performance.
Also, deciding how much to trade is simple math, and actually, it is the professional approach to trade with fixed lots.
Regarding the complete Portfolio Backtesting, keep in mind that the EA Studio is limited with MetaTrader on the other end. And on MetaTrader, the EAs work on separate charts. The portfolio EAs work on a one-time frame and one asset. So even having a mixed portfolio in EA Studio would be useless because MetaTrader wouldn’t allow it.
Let me know if there is anything else. There have been many updates recently in the EA Studio, and I will drop them a bit later on this topic.