I’m generally looking for an approach to converting the latitude and longitude I can get from Google Maps to UE world units. In my case, the area I work with is relatively small, so either a flat / projected or round / spherical conversion should work. Ideally, my UE world’s 0,0,0 should start at a specific latitude and longitude that I have picked in Google Maps as the center of the area I work with.
Thank you for any hints. 
What I tried:
Reading about the Georeferencing plugin, I quickly realized this task is way more complex than I thought. I can’t seem to be able to set the plugin up in a way to give me sensible converted numbers.
As far as I’ve searched, Google Maps and Open Street Maps use the EPSG:3857 coordinate system.
The best settings I could figure out:
Give me roughly the expected conversions if multiplied by 100 000 (still the converted world location is about 100 meters off somehow).
When I travel around the map with the plugin’s debug widget, I get really strange numbers:
Which makes me believe my setup is wrong rather than the conversion itself.