There are quite a few guidelines out there for lettering with SLS, so I would suggest you go and look for one to refer to get all your details right. Personally, I think your font size seems way too small for SLS. Generally, nothing smaller than 14pt (about 5mm) is recommended. Bigger would be better. Your line thickness should not be less than 0.5mm.

Recessed text tends to have better resolution than raised text, so if you’re trying to keep it small, that might be a better option (but still not as small as 2mm!). If I understand correctly, this recessed format appears to work better with serif fonts rather than sans-serif.

Vertical orientation in the build envelope gives better resolution than horizontal orientation.