No. Rituals can be performed back to back or in ways that easily flow into one another, but they cannot be performed concurrently. I’ve spent a Charge I obtained from a Ritual. How do I get that Charge back? First, you must have no Charges of that School of Magic at all, either by spending them or simply “Revoking” them (taking 3 seconds of concentration to divest yourself of the charge(s)). Then, you must successfully perform one of your Rituals. This Ritual becomes “Active” and cannot be used again until you are carrying no Charges from that School of Magic.