Are portable waypoints consumed when placed, or is it sufficient to craft one, once unlocked?
A brief Google search reported that sadly the Portable Waypoint gadget is not reusable and has to be crafted multiple times. Also, it only last for 7 days at max after being placed (or less if you remove it before expire date).
Once placed, there is no way to remove it and get a refund.
Apparently so far only the Wind Catcher, the NRE and the two Geo and Anemo Treasure Compass can be reused.
Source: wiki and multiple post on the game official forum.