Do note that, depending on what plan you were on before, and what you're on now, it might be the same network but not the same service. Almost all MVNOs are at a lower data priority (sometimes by several levels), most don't offer roaming service, most don't offer international service, and things like (first-party) call/text blocking through an app isn't available.

I have a second line on tello for $6 and it's everything I need for that line, but during the day data is basically useless on that line. The tower near me is massively over capacity - but if you have a tmo line with their top priority (most plans sold directly thru tmo), you'd never know it. Everyone else gets screwed.