No ~ I tried, and it took about 45 minutes. I started from Shanghai University, took Line 7, took Changshu Road (13 stop), directly transferred to Line 1 (5 stop), and went straight to Shanghai for ~ 5 RMB.
If Line 7 changes to Line 3, the waiting time at the first stop 19 and Line 3 will be longer. Slower than the last one ~