I said what I did based on previous rulings of similar questions. Such as "Q: If I Spirit Recall while in a golem does the golem go with me? A: No. The target of the ritual is the Spirit, therefore only things attached to the Spirit travel with the Spirit." Therefore, I assume the reference to dissipation is specific to the character's body (whether it is somewhere else or Body Stored inside the golem), not the Magic Item in which their Spirit currently resides.
However, the Obliterate scroll does have specific rules related to Controlled Spirit Store, Curse of Undeath, and Transform to Greater Undead listed (even if they are intuitive and a little redundant). It would make sense to me that clarification regarding Spirit Store inside a Master Construct also be included. Such a clarification would likely require ARC action.