For everyone asking for visual effects, I'm going to post a response of mine here that shows you the current status of the topic. It is pretty in depth and should answer you most questions, if not, just ask!

"It is not about making a bubble model and just scale it over a grid with physics off (yes, either you have FULL physics or NONE, which means that your approach for making a bubble that also has a hitbox overlaying the ship is impossible); the thing about modding a lot of games actually is that you don't know what approach is even possible within the restrictions the games gives you, and you have to find that out for yourself through tiresome research and tinkering non-stop with the API, and also checking if that what you use is even allowed for scripts. Also the fact that debugging is really hard, because you have to write indicators for all possible issues yourself, doesn't make it easier. But now I want to give you an overview of all approaches to "just shield effects" that I tried until know:

1) Overlaying a bubble over a grid when it gets hit.

The fact that the games gives you almost no control over the physics properties and visual appereance of objects and how hitboxes are handled due to Havok and optimizations means that the only option to do that is premaking transparent models that look like bubbles with different colors, generate one of them on a new grid, setting the new grid's physics calculations to false and position it over the ship's grid with an appropriate scale. Now all you can do it making it invisible or visible, no alpha slider option. So it is only possible to make it flicker on hit, or have even more bubble models with different alpha values that get played through like a gif (that's like around 80 models you need now). But it would still look weird as you cannot shoot on the bubble, what would feel natural, but only on the ship. It is like all other approaches purely visual.

2) Projecting an outer shell over the ship that behaves like the bubble visually (my second favorite)

While the general concept is based on the same principles as the bubble, the model "file" is different. This time, the "shield effect grid" consists of special shield like looking armor blocks that has the shape of the original grid plus one block size. While I like this approach a lot, the calculations you need to not only determine the current form of the ship and replicate it, but also scale it in one block size (as just scaling the same form just does not work and looks off) is something that a computer has a hard time to handle within 1/60 of a second. Maybe I can find a way to hook into the general block adding and removing events of a grid, but that not only needs further research, it would also mean that collisions would take even more calculation time as things get shredded to so many new grids.

3) Projecting a scaled shield block grid over blocks that got hit

This is the most doable approach overall, also based on the same visual principles, but instead of having one shield grid for the whole ship, you have one for each block that got hit recently. It looks okayish, but the blocks overlap because they are scaled around 1.1 each. Also, if you have AoE weapons and such, a lot of those grids get generated which is also problemating for client performance (these grids are not synced by the way, so at least network traffic isn't an issue).
This is the one I'm going for at the moment.

4) (Probably impossible, but favorite) Projecting a ripple effect with fitting coordinates and direction when hit

This would also be a nice solution overall, unfortunately the DamageSystem where I get the damage events from does not forward exact hit information like coordinates and directions to me, only the general block that would take damage (if I don't prevent it). So I have no way to know where and how to place that effect. Until now I have not found a way to find that out, and if there are no changes to the Class Whitelist, I don't think this will change."