You can omit the 13, enum numbering continues after the 12.
But I think we have to wait for betacentauri's comments, he knows the exact reasoning behind the 12, and he can tell you whether 13 is a good idea (or perhaps we should skip even more values to avoid conflicts)
Thank's I was not shure what it would have done whitout the =13 behind.
But in the mean time I already did experiment and tested with the cDDPPID=13
vuduo2 ok also after reboot channel audio stream setting is retained selected and works.
For that I have here the patch 3
Now it's just waiting on betacentauri's comments if it's ok the 2 patch or the three posted here.