Can Beacon Effects Stack?

Does effects from beacons stack with another beacon with the same effect? No, but if they spread different effects, both with be applied.

Can you have multiple beacon effects?

You can have multiple beacons.

Do temporal beacons stack?

First off, the Temporal Beacon is simply a more advanced version of the Beacon card, which you get early on in the game. It increases the movement and attack speed of all units within its radius, and the effect can be stacked, allowing you to get through a particular area of the loop more quickly.