Hmm. I just discovered the Minable Captive Biter Spawner mod. It complements this mod nicely for cases where nudge moving isn't enough. I've been wanting to move a promethium ship egg launcher field with 1440 legendary captive spawners directly inserting into silos. I had relied on the previous versions of this mod extensively over the last few months for adjustments.
For what it's worth, it makes sense that things like pumpjacks aren't movable - the player has absolutely no choice in positioning of a pumpjack. However, captive spawners are placeable in the base game at a location that is entirely the player's choice. If they were like pumpjacks where their location is tied to a resource patch then a restriction could kind of make sense. But they are not.
If it were possible to differentiate originally-wild captive spawners vs player-placed ones then that might be an alternative.
