Didn't tried it but:

Reaper healing is limited to lv84, which means you can't benefit from the big regen in potd or HoH.
Shroud is a lv80 ability which means a good chunk of your DPS is locked and you're bound to 1 2 3 and Avatar gauge in potd and only adds Gibbet action.

I doubt it will shine more than GNB and MCH but I don't have the practice to it.