/dtoverlay/config.txt does not exist in Android 11 v1.0.0 Tinkerboard S R2.0 release.
There are only cmdline.txt file and overlays folder:
WW_Tinker_Board:/dtoverlay $ ls -la
total 24
drwxrwxrwx 3 root root 16384 2021-12-14 01:16 .
drwxr-xr-x 25 root root 4096 2021-12-14 00:43 ..
-rwxrwxrwx 1 root root 58 2021-12-14 00:46 cmdline.txt
drwxrwxrwx 2 root root 2048 2021-12-14 00:46 overlays
WW_Tinker_Board:/dtoverlay $