Whomever designed the Kratos kit at Games-Workshop really understands their customers. It doesn’t even need much magnetization to keep all the loadout options available. Really only the top plate of the turret needs magnets. Everything else can just be swapped out securely enough.
Hull Weapons
First the hull weapons. If you are careful about lining up the two halves of the pivot assembly for the hull weapons you can literally just pop them in and out without any modification. I’ve left the top plate of the hull unglued to make getting the pivots painted easier.
Sponsons
The sponson weapons have a few different ways to allow swapping out. I did a little digging for how people were going about it and found the simplest and least fiddly method without using magnets. The actual sponson mounts are already designed to be removable (praise the modeler) so it will be easier painting and storing. But there is only the two mount assemblies. The weapons can be swapped out simply non-the-less. Glue the bottom plug in the mounts and snip it flush. Now you can slide a weapon in and place the top plug with the sensor bulb and it will hold very well and the way it is notched makes it pivot with the weapon so it looks good doing it.
Turret
The turret is really where the designers seem to have put some thought into modularity. If I’m honest they probably could have gone just a step or two further and it would be a no-brainer, but I understand the need to get the things done and not complicate the mold too much.
The turret weapons have pivot posts that allow them to be held securely and yet pivot up and down when the top is glued down. By magnetizing the top plate of the turret rather gluing it you can easily swap the turret weapons. You can also fairly easily magnetize the specific decorative accessories that mount on the back of the turret for each weapon. I’ve opted to just mount the Vulkite one as it looks cool and I will likely be running that most of the time anyway. I’ve seen some do the traditional front loading magnetized weapon on these, but this simplifies things so much without worrying about the weapon seating straight. There are other hurdles with the removable top plate but it is a little easier to adjust as you go. I’ve placed a second magnet far forward beside the gun to ensure the weight of the main gun doesn’t cause the top to unseat at all. It all holds very securely.
Cupola
The cupola/hatch/pintle weapons are pretty straight forward magnetization. A sheet of styrene under the hatch opening with a magnet in the underside. A touch of greenstuff and a magnet to mate with it on each hatch. They gave us 4 hatches and the havoc launcher has its own hatch. So you can have all the options available. The only caveat seems to be that 2 of the hatches don’t allow combi options even though the build instructions and the datasheet in both 30k and 40k don’t have non-combi options. But it is simple enough to imagine a bolter there isn’t it? I’ve opted to not use the marine popping out holding a pintle weapon as this will be used for both my Space Wolves and my Iron Warriors the same as my Landraider.
Overall, this was a dream of a kit to build. It was so easy and everything lines up perfectly. It is night and day compared to even the recent Primaris vehicles and lightyears better than the old space marine vehicles. It will be tedious getting all the bits painted, but I plant do simple metallic weapons with some red accents to keep from getting bogged down with that.