I’m almost 2 decades late, but I have some insight:
Cummins Court would have been an intersection somewhere between 107 and 108 James Street. According to the 1835 Dublin Almanac, 108 James Street was the residence of my second-great grandfather, James Cummins, who was a harness maker and saddler. As far as I can tell, that was the family trade for at least three generations. After my family no longer resided there, the property was owned by a tobacconist until Guinness ultimately purchased it.
I am not aware of the origin of the name Cummins Court and I am presuming the connection to the family name is a coincidence unless my ongoing research proves otherwise.