Honestly, there's no "Right" answer here. This is a rules decision, and rules, by their nature, are arbitrary.
Remember, there are two main audiences for GC3:
1) the "causal" player; people who are going to spend 10-20 hours/month playing. They're not going to know advanced strategies, and they're going to play the "surface" of the game. Rules for them need to make sure that there's no major cheats easily available, and no super-powered strategies that always win AND are easily executed, because then they'll not play the game at all after figuring that out. So, they'll probably avoid the DLC/Expansion packs, since the game isn't as fun as they thought.
2) the "hard-core" player. Those of us (mainly on this board) who will easily spend 100 hours/month. We'll try all sorts of different strategies (including some brain-dead or low-probability ones), just to test out where the edges of the system are. Rules that constrain play for us tend to be bad, unless the behavior is truly game-breaking.
Sensor boats are something that really shouldn't be available for #1, because they're going to be playing on smaller maps (because they want to finish within a reasonable amount of time), and they severely reduce the challenge of the game.
For #2, it's more of just a majority opinion about the "brokenness" of sensor boats.
Personally, I'd go for a default rule that constrained sensor boats, to keep the default behavior OK for group #1. StarDock could add a "cheat code" to type in, which would enable some of the more "power player" abilities. Since I expect that there's going to be lots of these kinds of things.
That is, my opinion is that we should make the game default to being "fun" for the casual player, and then allow hard-core players to enable different rulesets via "cheat codes" - they're not really cheats, it's just altering the base behavior.