Hey Roman,
you are very right here, OOS is very important, but once again the update now changed it a lot. We have the chance to choose acceptance criteria for the In Sample and for the Out Of Sample. Before it was for the complete backtest.
Personally, before the update, I did not use a lot the OOS. Simply because we were choosing the acceptance criteria for the complete backtest. So no matter what was OOS showing we were able to decide which strategy to use based on the whole test. Now we have it separately. This way we can choose what criteria to have in the generated part(In Sample), and what Training part(Out of Sample) to choose.
With simple words, now we really have the chance to simulate Demo trading with OOS.