“Overstaying” for a bit?

I am attending a business workshop in Germany, so I applied and obtained a C-class Geschäftvisum Schengen Visa which is good for a year and 90/180 rule applies.

During the application process, I am asked to submit a business schedule in my application, in which I declared I am staying for 8 days in Germany (a Sun - Sun schedule) with consistent days being filled in the application form as well.

A long friend of mine heard the news that I am coming to Germany and invited me to stay over for a bit. She’s in Schaan, Lichtenstein. With her invitation, I am thinking of extending my stay in the Schengen zone for two days, hence returning to my home country on Tuesday the next week.

So my question is: within the granted condition of my visa, will deviation of my intended day of departure and itinerary get me into trouble?