Hi guys,
I have a couple of Syrian Rue seedlings growing quite happily.
I'm wondering how much seeds these guys produce when they reach maturity? For example, is one plant sufficient for someone who takes Ayahuasca once or twice a month?

Any information is greatly appreciated.

A fully mature 4 or 5 year old plant might produce that much.
I'd say grow out all you can and remove any less productive plants only when your seed yield clearly exceeds your needs.
In their second year when each plant makes one or two doses you'll be glad you did

It's not unusual for P. harmala seedlings/ young plants to die completely back to the roots from time to time when cultivated in pots and outside of ideal desert environments. So, don't give up right away if it seems to die on you. That said, they're notoriously difficult to grow as a thriving, mature plant in pots outside of an appropriate desert environment where they can grow as a weed.