First off, no combat modules. That's a pretty safe decision.
How this would work, is you install a bay in a size 3 through 8 slot. This allows you to install certain modules into the same bay. By default, most things won't work, but there's a fairly obvious few choices of what could, and remain balanced. A few tons of bracing and power coupling, probably 1 ton per class in mass? And some money, whatever.
No: Fighter hangar. Fuel scoop. SRV bay. AFMU. FSD Interdictor. Shield generator. SCB.
DEFINITELY not: Bulkheads of any sort.
Cargo rack: yes. You only really lose with them, if you install one into a size 8 bay, you could fit in a size 1 and size 7 rack, for 130 cargo, instead of 256 from a size 8 rack. Still, this will allow a ship to sacrifice a size or two, to get 4 cargo for limpets or other niche uses. No real advantage other than that, that I can see. I suppose you could put in a lot more corrosion racks? Maybe not corrosion racks...
Passenger cabin: Why not? It's not an advantage to have multiple smaller passenger cabins. No real reason to shoehorn a small cabin in, but whatever.
Discovery Scanner/DSS/docking computer: My personal wants. They offer no combat advantage, and large ships waste large bays with a tiny little scanner in the middle.
FSD booster... maybe not? Maybe? Probably wouldn't affect much. (The guardian module.)
Refinery: Probably not.
Limpets: Kind of a special case. As it stands now, no. Because multiple size 1 limpets are superior to higher size launchers in everything but range. Limpets are in a weird place now anyway, we all know it. Better than scooping manually, but not nearly enough to justify the downsides and annoyance. Still, having a multi-limpet-type bay would be useful in a lot of scenarios. IMO, limpets need a full rede
Fuel tanks: Sure, why not?
The big problem with all this, is combat builds and stacked bulkheads. It's not a problem with non-combat modules, this problem is baked in simply because combat modules CAN stack.
And people can and will stack them as much as possible.
So... combat modules shouldn't stack. Seems kind of obvious, let ships have one bulkhead reinforcement, one module reinforcement, and one SCB. If the combat stuff is limited, the NON-combat stuff can be more generous. Combat ships might even pass on modules in favor of simply being lighter.
In the same vein, shield boosters shouldn't stack up to all the utility points, either. Since a ship can have 2 reinforcements, allow them to have 2 shield boosters. (And this would nerf my OWN shield by a chunk.)
How this would work, is you install a bay in a size 3 through 8 slot. This allows you to install certain modules into the same bay. By default, most things won't work, but there's a fairly obvious few choices of what could, and remain balanced. A few tons of bracing and power coupling, probably 1 ton per class in mass? And some money, whatever.
No: Fighter hangar. Fuel scoop. SRV bay. AFMU. FSD Interdictor. Shield generator. SCB.
DEFINITELY not: Bulkheads of any sort.
Cargo rack: yes. You only really lose with them, if you install one into a size 8 bay, you could fit in a size 1 and size 7 rack, for 130 cargo, instead of 256 from a size 8 rack. Still, this will allow a ship to sacrifice a size or two, to get 4 cargo for limpets or other niche uses. No real advantage other than that, that I can see. I suppose you could put in a lot more corrosion racks? Maybe not corrosion racks...
Passenger cabin: Why not? It's not an advantage to have multiple smaller passenger cabins. No real reason to shoehorn a small cabin in, but whatever.
Discovery Scanner/DSS/docking computer: My personal wants. They offer no combat advantage, and large ships waste large bays with a tiny little scanner in the middle.
FSD booster... maybe not? Maybe? Probably wouldn't affect much. (The guardian module.)
Refinery: Probably not.
Limpets: Kind of a special case. As it stands now, no. Because multiple size 1 limpets are superior to higher size launchers in everything but range. Limpets are in a weird place now anyway, we all know it. Better than scooping manually, but not nearly enough to justify the downsides and annoyance. Still, having a multi-limpet-type bay would be useful in a lot of scenarios. IMO, limpets need a full rede
Fuel tanks: Sure, why not?
The big problem with all this, is combat builds and stacked bulkheads. It's not a problem with non-combat modules, this problem is baked in simply because combat modules CAN stack.
And people can and will stack them as much as possible.
So... combat modules shouldn't stack. Seems kind of obvious, let ships have one bulkhead reinforcement, one module reinforcement, and one SCB. If the combat stuff is limited, the NON-combat stuff can be more generous. Combat ships might even pass on modules in favor of simply being lighter.
In the same vein, shield boosters shouldn't stack up to all the utility points, either. Since a ship can have 2 reinforcements, allow them to have 2 shield boosters. (And this would nerf my OWN shield by a chunk.)