Thanks for the reply! I have considered this idea as a potential solution, which would overcome some of the hurdles of Android's SMS limitations. However, I think the real bottleneck for sending SMS would inevitably be the carriers. Though once I can get some more hardware on my hands, I'd love to try this idea out to see how feasible it might be. In terms of hardware requirements, it would still be a much lower barrier to entry to create a server app that houses the cellular modem and internet abilities into one single package, since no extra hardware cost would be required for small scale operations. But for larger operations, this is definitely the endgame assuming carrier restrictions allow throughput to be faster than achievable with Android.