Hudla, Thank you!
this issue of the landing dist proc of a damaged engine brought a lot of controversy, because it wasn't well expressed in the QRH and many thought that every time you had such failure you had to do a landing dist proc Later on they fixed it and now it is clear that only in case of ice accretion you have to do it. In 320.
Airmann
The bleed from the opposite system will reach not only the users such as WAI or PACKS, but also the faulty engine bleed valves. If there is damage, bleed air could make things worse, maybe leaking into the nacelle and increasing fire risk or who knows what... It seems to me that as a precaution, you have to isolate the affected bleed channel.
In the 330 we will lose either the blue or the yellow hydraulic, because we don't have PTU. This leads to loss of two spoilers per wing, which leads to a landing distance procedure. Once you are there, you have to use CONF FULL vrefs. So they have to add a deltaVRef only to account for the CONF 3 situation. As you say, there is no abnormal configuration, here, and CONF 3 VAPP could be used, imho.
cheers