https://i.imgur.com/APg0kFk.png

Invis has determined that there is a special set of powerups that only spawn engines, on Iokath.

There is also some evidence that the regular powerups (the powerups that can be weapon, engine, shield, or very rarely, damage overcharge) are in one cluster that is spread across the map- on the other team deathmatch maps, these seem to be more regional in nature.

The map Invis has provided (the above link) has purple dots as the cluster that only makes engines (the newly discovered Invis Cluster), with the red dots indicating the damage overcharges that whose locations are more familiar ( https://imgur.com/a/zchJPHC ) for reference.

The fifteen possible locations highlighted in purple will always be engines, and a maximum of three will be up at a time.