Very long boil to hit gravity

[rustynails223]

Hi I brewed a belgian dark strong and was having a hard time hitting my 1.103 target gravity. I was planning on boiling for 1.5 hours but I ended up boiling for more like 3 hours because my gravity was too low. although the hops were only boiled for 60 mins. I may have just used too much water because after the very long boil I still ended up with 5 gallons in my fermenter. should I expect getting any off flavors from this like kettle carmalization or any thing?

 

[MalFet]

Potentially some increased carmalization (Maillard reactions, more accurately), which wouldn't be a bad thing in a dark strong. I wouldn't worry about it.