The SG are notorious for producing grainy solids in lighter tones, because they have no light colors. In addition, the TR-2 is higher pigmented, than earlier inks. This means, less but darker dots are printed to achieve a desired color.
From what I can on your pictures, the dark red looks like beading or pooling to me. This is a material/heating/printspeed problem.
On one photo, I think I see unsharp edges of the patches. This is normally a bad M-Gap adjustment.
Then, there is one thing, that is very annoying...
Roland thinks the two channels on printheads fire at the same speed, so only one channel needs to be adjusted. (This was their misconception starting with Epson and they do it with Ricoh as well)
When adjusting SG's (VG's as well) the CM head is sometimes so badly off, it needs replacement. Otherwise, you will never get a decent quality.