Some people actually use other features of the program to establish robustness.
I will share a couple ideas...... once you get your strategy looking good...... you can
change the dates in the current time frame.. that is quite similar to OOS
see how it does in other time frames.......
see how it does on other instruments and varied time frames.
One thing that i like to do is to export to MT5, lots of timeframes and instruments.
Easy to do forward testing because the data goes back a long way. (MT5 is not as accurate as FSBPro)
If you are into coding, you can take the EA and make a few modifications so you can optimize in MT5; further, you can build an EA to optimize your EA on multiple instruments and multiple time frames.
FSBPro has many tools and many ways to accomplish what we need. Working with each tool for a while will allow you to have ideas to create your own solutions.
No matter what we do to create our EA, the final test is what happens in a real account, live trading.
Popov has shared many ideas and methods, it is up to us to use those and others and create our own solutions.
I like to do a backtest in MT5 with the indicators brightly coloured and examine every bad entry to understand why it failed and how to compensate for the error. This takes a lot of time because I like to look at many bad entries...to get the cause of the error. You can do this also in FSBPro, I prefer MT5 for my own reasons, mainly because I will perhaps adapt the EA so that I can optimize it in MT5, that is just my personal preference.
In summary...... you can do OOS or you can use different periods and different time frames and different instruments.
I hope that gives some ideas.
My 'secret' goal is to push EA Studio until I can net 3000 pips per day....