Main stack drain question

[16speedster]

Hello - I am remodeling an older house in Wisconsin and am adding a bathroom on the second floor and a tub in the basement. I am connecting to a T in a buried vertical cast line that runs to the septic tank. I am crowded for space so used a 4 inch sweep T with a 2 inch reducer that connects to the tub p trap. Before I patch the floor I am hoping to get some advice if this configuration could be prone to plugging issues. Thanks!