Ciao Nick
To follow on from @Jedd’s suggestion, within the QGIS Connector, you can set the proxy origin as a custom CRS.
This assumes you select a Lat/Lng value from a Geocentric CRS. Speckle Connector will then centre a Projected CS at the coordinate you specify, which will bring data in at the Blender origin relative to that coordinate.
If you have difficulty working out your current projection or coordinate system, follow @Kateryna’s suggestion here: CRS and project center in QGIS - #6 by Kateryna