Slack additionally decides to hard-reload itself, seemingly without reason.

I work on the road (from a train / parking lot / etc) for five or six hours per week. My T-Mobile plan is grandfathered in, so I can't "upgrade" to a plan that allows full-speed tethering without considerably impacting my monthly bill.

Realistically, I hit around 1.5Mbps down. When Slack reloads itself, I have to stop _everything else_ that I'm doing, immediately, and give Slack full usage of my available bandwidth. Often times, it means taking my phone out of my pocket, and holding it up near the ceiling of the train, which (I've confirmed in Wireshark) reduces my packet loss. Even then, it takes two or three tries just to get Slack to load.