WE don't focus too much on "chakras" in SFQ, as that is from a different energy system.
However, the heart center, is definitely opened up a lot doing Small Universe meditation. And one can "linger" for a few breaths when one gets to the heart before moving down again into the lower tan tien.
Also, Level 2 works more with the middle tan tien, which is just below the heart.
And Master Lin, in a lot of his meditations works with heart energy.
Hope that helps.