This is something I’ve wondered about too. Normally I will just do a simple basic calibration using something like digital video essentials DVD and blu ray (since calibration should be different for SD and HD) and leave it at that, but with the OSSC profiles there is the potential to calibrate with more granularity for individual consoles. I wonder if this is something someone with a fine eye for detail like FBX could comment on?
To answer the second part of your question if you’re doing just a basic calibration (i.e you don’t have a colour meter) then things like HD video essentials will give you a bit of coloured plastic to look through, when e.g Red is calibrated as close as possible you can tell by looking through the plastic as it will match whats on the screen. It’s crude but better than nothing.