Huh. The spacefolder's stave works on the Hunters of Huanchi, to guide celestial reinforcements out from hiding in the bushes.
Yep, doesn't specify the types of teleports it works with, only that it trigger the next time you remove and set up a unit. This means it also works with Tunnel Master.
Not in the same turn, though. Tunnel Master is done instead of picking a unit to move, which happens before you can activate Spacefolder's Stave (end of movement phase)
Oh you're right - weird rule. I suppose it's intended to be used with Draco's Tail reinforcements which is weird seeing as it can also be taken in Fangs of Sotek.
In sure it's intended to be used with Dracothion's Tail as well as summoning. So in Fangs of Sotek, it can still be used with summoning, which is worthwhile in its own right. As we've seen, it also works with the Hunters of Huanchi, and with Terrawings' Symbiotic Relationship ability. All these abilities occur at the end of the movement phase, when the stave's ability is declared. Using it with Spatial Translocation and Tunnel Master and the endless spells Soulscream Bridge and Lauchon the Soulseeker — in a subsequent turn after the movement phase the stave's ability is declared — technically works right now, but will probably be erreta'd away.