I just use the windows explorer with large thumbnail view to quickly review 1000s of pictures for real bad ones (up side down ones). Its not the scrollable 360 view but simple equirectangular jpeg which is fine and quite fast (as normal jpeg). I am only using the LG 360 viewer on my desktop to impress friends… It agree, that viewer is very slow, even uploaded mapillary 360 sequences can be accessed faster online on the mapillary website.