How to add grain to my images with RT?

Some of my photos are just a bit too clean, while others would benefit from a bit of graint o mask some “artefacts” due to sharpening and general processing.

I’m using RawTherapee (ART won’t launch, and I really don’t like Darktable) and there doesn’t seem to be a way to add grain. What I do now is do my processing in RT and once done I open the image in GIMP where I add some HSV Noise, but that is far from optimal.

On the one hand because I would like to avoid bouncing between applications and on the other because the options for HSV Noise in GIMP are really not that great, tbh. What I’m hoping for is something like Capture One does it, where you can chose different grain types, their impact and ] coarseness/granularity.