Improve quality of the Text scans.
Text scan (Gray) have less information to process, that't why is about 3 times faster than color mode. Unfortunately the quality of text scans are not good, as it is converted to 2 bit (black and white) images. To improve that conversion to black and white images was disabled. As a result the images have good quality, and the scanning process is fast. To scan images to black and white, the Lineart mode should be used. Unfortunately it is not supported by UX design.