I dun know that 115 is under bsep...
Oh, maybe you should ask our friend SMB128B who can give you a big
lecture on how other services cannot get service downgrades because
of BSEP, even if they are not under BSEP.
And honestly, I now tend to agree with him, because SBST has not
done downgrades to any service in the last 6-8 months as per my
knowledge. More than taking out DDs from 163, need to take out
buses from 163M that are completely redundant.