More size for free annotation

[un-lo-so]

Hi!
I use sumatra pdf as my default pdf reader. Sometimes I try to repair electrical equipment, so I must consult electric schematics, they are often pdf files :-)) and it's comfortable for me add note on schematics. Unfortunately the minimum size of "free text notes" is 8 but in many situation this size is too big for me. Of course these kinds notes are useless for printed version but no if one consult pdf on a PC because these notes\reminder prevent to change page frequently.

So, my qeustion is: it's possible to reduce the font size?