Hi, do you really need that many active collisions?
I don’t know how your setup looks like (never played Space Engineers), but maybe you could group your ships into parts (so each part would hold an array of mesh references and/or references to box collisions, not the actual meshes) and enable/disable all the collisions in the part based on the distance to the player. So you could check on a timer the distance of the player to the parts you have created.
And I would do the grouping into parts automatically via an in editor script.