I’m interested to know though whether corrected camera positions can be exported. I believe that camera positions are adjusted during processing. If ground control markers are used with an accuracy of say ~2cm, what accuracy of corrected camera location Do you think you can expect?
You can export the external camera parameters. More here: https://support.pix4d.com/hc/en-us/articles/202558499#label1
When you reoptimize the influence of the GCPs is taken into account in these parameters (position and orientation).