First, I’m afraid we use all available real estate on the Renesas MCU, so there’s no room available for additional firmware. We actually use a more powerful than standard MCU compared to typical LoRaWAN systems specifically to handle the additional complexities of Symphony Link and we use all of it.
A secondary MCU is required for all applications.
Second, we will have modules for the 868 MHz band down the track however, due to the external RF components beyond the SX1276 that we use, the 868 and the 902-928 module will not be the same. They will be the same form factor and the same pin out, but there are RF performance differences between the modules which limits their effective bands.
While we could certainly entertain the idea of a single module that can be utilized in both bands, we’ve found it’s typically not cost effective for most applications due to the additional complexities and cost.
We do not currently have anything in the 433 MHz band in our development queue.