Wifi & Bluetooth settings for location service

whats the service behind the options to speed up location fix with Wifi and/or BT? Does it send data outwards and tho whom?
With Google Android it does as far as I know.

Any other settings (or apps) you use to aid location fix?

With microG 0.2.27 one could use various backends that mostly collect, not send (much), data.

The current microG 0.2.28 used in recent builds has changed and uses integrated functionality, Mozilla Location Services being the core provider.
Open the microG Settings and head to the location section for configuration.

If you want to know what it is and how it works see…

MLS - Overview

Mozilla Location Service - Wikipedia

Thats interesting, though I dont understand to much being “just a user”.
seems to me opting for Wifi & BT for aiding location fix is not much of a privacy threat. I guess also it will not make to much of a difference for battery runtime, lets see…