The area calculations in my project derived from the attribute field show values way below actual area, because the attribute field assumes the project CRS (EPSG:3857). However, this CRS should remain unchanged as it is the same CRS used for the Bing basemap in the project. The layers in my project are projected using ESPG:4326. This should also remain unchanged as this allows the correct lat/lon to be displayed.
Note - when using the measurement tool or adding geometry attributes the correct area (or close to correct) can be displayed by calculating ellipsoidal area.
My project requires that the attribute fields are pre-determined, so the previously mentioned techniques do not seem viable solutions.
So, given that the project CRS is not suited for calculating area... is there any way to correctly calculate area in the attribute field of a QGIS 3.4.3 project with multiple CRS?