Yes, MConverter offers three levels of compression: basic, strong, and extreme.
With basic compression, some optimizations are applied to the document, but the PDF quality remains essentially the same as the original file. This setting is for preserving fine details.
With strong compression, there is a much larger reduction in size. The quality remains visually identical to the original, unless you zoom in very closely.
This is the ideal setting for scanned documents, so that you can email them. Text and signatures remain perfectly readable while the file size may be shrunk by more than half, depending on the scanner used.
Extreme compression may reduce the quality of the PDF slightly, but you’ll achieve the smallest file size.