Thanks, but you misunderstood.
My question is about where to change the bigness of the LO-UI fonts.
I know, there is a setting in LO where you can zoom the UI up to 130%. That's *not* what I am looking for.
But there must be something (systemsettings/font/???, gtk/whatever,

) the LO-UI font bigness relys on. That's what I am looking for.