My understanding of a progressive jpg is that it saves the color information of each pixel in a different order, to create the progressive loading effect. I.e. instead of
RGB RGB RGB ..., it's saved like
RRRR... GGGG... BBBB.... (https://imagemagick.org/script/command-line-options.php#interlace)
If this is true, is it possible to convert a jpg to a progressive jpg without any loss in quality? It seems to be reordering of data rather than needing to go through the jpg compression algorithm.