Gonna go and throw my hat in the ring with the folks that want it removed completely. Initially I was on board with the inclusion of a disconnected area for ship design and all that, but I hadn't considered the ramifications of removing that research & development aspect from the MMO world. Personally, having the 'offline' area available means I'm always going to feel obligated to take my ship, station, or other contraption there in order to run tests before bringing it to the online world, no matter how small the change is. Having players wink in and out of existence like that (as building things is very central to this game) I think could make it feel less like a living and breathing world, and more like a showcase world where there is no room for less-than-perfect designs - something the build servers from Garry's Mod suffered from greatly, in my opinion. Space Engineers in particular suffered from having both a prohibitively expensive survival design process coupled with an unlimited creative mode, to the point that it felt like a waste of time to design anything in survival without first 'trying it out' in creative.
Another important argument I feel is the economy of the thing. Offline editors do promote more advanced and technical builds, but completely eliminate the investment of ship building in two distinct ways: material cost, and 'jobs lost'. While ships designed in the offline editor will still need to be purchased and/or built in the online world, the economy loses the stimulus of research and development not only in the way of materials, but also in the need for teams of people contributing to the work, whether they be engineers or just endos with build tools. With the offline designer, no faction (and certainly no individual) will want to spend their credits on prototyping and design when they know they can hammer away at it in the offline editor. This means that not only are players not purchasing or mining for materials as often - and even in the end it would be lesser, as they'd have an exact materials list required - but also that there are ship builders whose hard work is less valued than it perhaps ought to be. I won't argue in favor of creating an 'elite caste' of ship builders, but it would seem to me that, as an individual player without a faction, I shouldn't be at all inclined to purchase a player-designed ship when I have the ability to infinitely prototype something to the point of having duplicated another design. Even if it means having to spend a little while with the build-tool filling it in, I save a fair chunk of change by bypassing the fee of assembly and design, and do so entirely by.. not (really) playing the game?
The 'immersion' is something I feel less comfortable arguing, as certainly there are many that don't particularly care for it. That being said, 'error' is a 50-50 partner in 'trial and error', and I think it brings value to the MMO world as a whole. Errors don't necessarily have to be punishing in Starbase, as safezones disable most damage; but the trial of building a thing in a public or semi-public space lends itself well to building an engaged and positive community, within and without factions. Clever builders can share tips in-person (in-endo?) to others, who then pass them on, and so on. New builders are introduced to all the aspects of ship building - weaponry, armor, thrusters, passive systems - but are also presented with the balance of each system, and learn to weigh the pros and cons of them against each other: eg rail cannons might be prohibitively expensive, and foregoing them can net you tougher armor, but heavy armor will weigh your ship down. This kind of feedback loop is readily apparent to experienced builders and players, but someone new to the genre may be completely unfamiliar - and with a fully free-form editor, the sorts of imperfections that come with the learning curve will hardly be tolerable.
Certainly, having an offline playground has its boons: players with spotty internet may still be able to play at least part of the game; some players may find the engineering aspect daunting without it; testing can be done ad nauseam; exciting and wild builds can be constructed; and so on and so forth.. but with the exception of the first, these are all things that can be done in the online world without being drastically detracted from, while also contributing to the overall experience of all players. Without a free-form editor, ship building becomes a more iterative experience where individual designs are encouraged and allowed to proliferate (in the form of the ship market); whereas with the offline option, I think we'll see much more of the 'min-max' type builds that, while providing instant feedback and experimentation, may stifle creativity in the end - even if both options end up having 'meta build' features.
But I do see value in having some form of a ship editor. I think, as long as ship-building is not prohibitively difficult or extraordinarily expensive, Starbase will benefit from a limited ship editor presented in much the same way as the station editor: a static blueprint inside the online world that players can configure to their liking, without actually allowing it to be interacted with or tested with before it's constructed. In this way, players can lay out and/or share their concepts, come to a consensus, and gain valuable feedback without losing the 'thrill of discovery' as it were.
anyways thanks for coming to my TED talk