There’s always a chance they run with UnifiedNlp (if they need network location) or with microG (if they need other Google services and APIs).
What infrastructure? Qualcomm hardware & drivers (low-level interfaces used by the system) need to comply with Google’s CTS and therefore they work through regular, generic APIs (high-level interfaces used by apps) in Android (Fairphone OS/Open and Lineage OS). I don’t know what are you referring to,
Many thanks for testing. I wasn’t clear however, Totem is the one that crashes without Google Services. Happy Cow and Citiz run with microG or Open GAPPS. They can all have GPS fix when they don’t crash, except for Citiz: with com.qualcomm.location disabled the GPS doesn’t turn on. The real problem however is network location. With GPS turned off the three can’t get a fix when Google Location isn’t available, Totem as I said crashes, Happy Cow will nag repeatedly that GPS and Google Location should be turned on, and Citiz will spin and never get a fix.
I forgot to add that microG can make Happy Cow and Citiz think that Google Location is available but I remember being annoyed by them not always getting a lock. The reason why I dropped microG is another one, it’s because of apps that complain about outdated Google Services. Open GAPPS naturally solves all problems, except again for the need to have Qualcomm service enabled in the case of Citiz.