NRO Icons are Compressed

[heare2code]

Is your feature request related to a problem? Please describe.
When using this program, the icon's JPEG compression is noticeable.

Describe the solution you'd like
Add an option to not convert the user supplied image to JPEG (if the image is already an JPEG).

Describe alternatives you've considered
Make the converted icon's JPEG quality higher.

Additional context
This program that also forwards NRO files has an option like this built in but does not work anymore.
Examples:
(Taken with bitmap-printer, so there's no further JPEG compression from normal Switch screenshots.)

Left: From Source Code - Right: From NSP Output

[heare2code]

Update: Found out the mentioned program does work, it was just me forgetting to set the JPEG to interlaced. I also found a workaround using this and using a higher quality JPEG instead.
Still though, I think it would be nice to implement this for other people who has the same issue.