I flashed a Dac+ PRO just fine using your image:
Works good, don't need to specify a dtoverly in /boot/config.txt.
( Need a Digi+ image now :) )
Is there also a way to undo this or still be able to specify a dtoverlay?
For some testing (the Kali FPGA i2s buffer) -- I need to set it to slave mode again :D (oops)