I don't know if you have come across this guide yet, but I would check this out (Digi Micropython Programming Guide):
This will help show you a robust set of features that expand beyond API mode and make it to where you do have a capable MCU that is cellular connected that also supports excellent sleep functionality. So for example, I utilize these modules for IOT projects that demand cellular connection, local edge computing ability, and also the ability to reach impressively low (for a cellular capable module) sleep currents. I am also able to utilize libraries to where I gain I2C functionality which was one of the main reason why I migrated to the Xbee3 platforms in the first place. I personally think the cellular module they have is a rich offering with a ton of potential.
Hopefully this helps build the case for taking the Xbee3 Cellular modules for a spin.
Also, as a side note, I was able to get up and running with a Hologram.io SIM which is another point. The ability to be more operator agnostic is a bonus, I am coming from the particle.io platform where you are locked into AT&T which does not always get it done, especially in remote areas. The Xbee3 Cellular is a certified product with multiple operators, including Verizon which historically seems to offer better rural area support.
Food for thought!