Nested grid impagination

Greetings. I have a grid with several nested grids.
First Question.I would like to change the font of the nested label (color / dimension) in order to make the beginning of a certain type of information more visible in the impagination, but I don’t understand where this change is made. I have also searched in the advanced settings of the theme but, perhaps also due to the bad translation, I do not find this setting.

Second question: I also do not understand why although there is space on the page, when I do the pdf export of this grid it puts a lot of useless spaces between the records of the same nested grid, ruining the layout.
Has anyone already happened?
I am running last version of SC 9.7.023
thank you