I tested a BL20X, had to tweak the WAN connection buffer size every few days when the speeds change with cellular and landline, the latency would be very high, a constant ~500ms which may not be an issue when streaming video, no issues when using two cellular modems. I also had to set it at 2000 to get the upload speed of the faster WAN. (~2019)

Unfortunately the cheapest models are at least few hundreds $ and reliable dedicated servers aren't cheap.