I should have probably clarified whether we were talking about to-go orders, because obviously you would tip at a sit-down place, similar to a sit-down restaurant.
For to-go orders, 1. and 3. are often because they use the same PoS (usually a Square or Clover terminal these days) for the to-go and sit-down orders. You are free to read accidents of technological convenience as social cues, but that doesn't automatically make them so.
2. is probably a true social cue, for either sit-down or to-go.
I tip to-go coffee shop orders (when there are clear tipping norms, as is the case at all the coffee shops I go to). You can call the POS system an "accident of technological convenience", but it is also a prominent, clearly legible sign expressing the expectation that you're going to tip.
It is less of a big deal to stiff a coffee shop than a restaurant (you might actually get yelled at at a restaurant!) but if you talk to them when the shop is quiet they'll mutter under their breath about the regulars who don't tip.
For to-go orders, 1. and 3. are often because they use the same PoS (usually a Square or Clover terminal these days) for the to-go and sit-down orders. You are free to read accidents of technological convenience as social cues, but that doesn't automatically make them so.
2. is probably a true social cue, for either sit-down or to-go.