Well, my suggestion is, in fact, implies less, not more complexity than involving an MCU with its own firmware, etc. Besides configuring the Bluetooth module to match the X20’s port speed and configuring the X20 itself in uCenter to output the right messages, everything else is just soldering and plugging things together.
I unfortunately don’t do custom work to order since it involves formal and informal liability risks. But I’d be happy to answer questions when possible.