I use GoPro’s to collect images (straight ahead and at 90 degrees across the road). GoPros dont have heading angles built in to the exif data. I used to be able to go into the sequences on the website and ‘normalise them’ to face the next captured image, and then offset the 90 degree images to actually orientate them correctly. This no longer seems possible in the website.
What are my options to correct hundreds of sequences?
Cancel that - I was not logged in! 
If you’re comfortable with the command line tool then that it is even easier as you can do both operations in one command.
For example to upload images I capture with a GoPro 5 pointing to the left I use the command line with the following options: “–interpolate_directions --offset_angle -90”.
That way they are corrected before uploading so no need to post process.
Yes, I have just been slack lately and dropping them into the desktop uploader. Time to get back to the command line.