Hi Matthias,
If you upload the project in cloud from Pix4D desktop, the project will be processed with same processing options that are selected (https://support.pix4d.com/hc/en-us/articles/202558589-How-to-upload-project-files-from-desktop-to-cloud). Otherwise, if only images are uploaded to cloud (https://support.pix4d.com/hc/en-us/articles/115004680703-How-to-upload-images-using-the-cloud-platform), cloud will process with the default 3D maps template. So for multispectral or RGB agriculture images, it is always better to start the project in desktop, use the processing options that will suit the best (ag multispectral or ag RGB for ag/homogeneous terrain) and then upload the project to cloud. In this case, the p4d file and the images get uploaded. Thus, the cloud will respect the processing options.
If you want a good reconstruction of the electrical tower, you will need to make a flight around the tower (orbital flight plan) and then merge it with this project. You can have a look at this for the flight acquisition plans: https://support.pix4d.com/hc/en-us/articles/202557459 and https://community.pix4d.com/t/4550-merge-nadir-image-with-45-image- for merging
2.) I changed processing mode in rig to optimize relative rotation. The resulting quality is more or less the same.
This will not change the quality of the output map so much. This option is mostly used for multispectral cameras not in our database… This is only when you want the point cloud of all bands.