Good question! Currently, OpenPPG remains focused on enhancing the solo flying experience, and while tandem capabilities are something we’ve explored in the past, they haven’t been our primary development area yet.
Tandem flying, especially with a trike, adds a lot of complexity both on the ground and in the air, which requires significant R&D. We’re closer now with the announcement of the improved 4.8kwh battery. We have also been working with motor and ESC suppliers globally to improve motor power and efficiency for electric tandem setups, but we don’t have anything officially ready for release. We want to do an electric trike right, and will let you know when its there 
If you’re looking for an off-the-shelf solution, gas-powered tandem trikes are a great option. I have the Xenit Trike by FlyProducts, powered by a Cosmos 300 engine. It’s got plenty of power and reliability, and it pairs well with the Vittorazi motor, which is quite popular among tandem pilots.
Battery technology is progressing, but for tandem flights of at least an hour, especially with a 300-350lb combined weight, gas-powered options still offer the best performance and cost-effectiveness at this time.