This would be SUPER important!!

I just thought very simple version of this would be something like once a single trade from a portfolio of trades has been entered don't open any more. This would help small accounts a lot in terms of risk management.

I think this would be a great feature. It would help get more trades on but in a safer manner. It could increase safety by ensuring trades with very high correlation only enter once but have a better chance of being entered as you start with multiple trades and their individual entry criteria.

Just a thought...

If you linked 2 strategies with this technique, say a Time-Window entry, with the single open condition if the parent strategy is open, there could be the potential with multi-day strats to trigger the child strat to open every day (generating many children to one parent, which might be undesirable).

Additional logic might be needed (like a strategy group ID or such), so that that strategy group would only trigger a child strategy to open once, or only if the strategy group didn't have a child strategy currently active.

In addition to strats with 5+ legs, could also be useful to replicate things such as PMCCs (with rails on shorts to prevent ITM settlement/exercise).