Faction strength system, voxel protection field emitter
Some time ago I played on a Minecraft server that had "factions mod" enabled. It made it possible to claim chunks, so that only owner faction could place/destroy blocks in a given chunk. This ability was limited by "faction power" if I remember correctly. This faction power was gained as faction killed other players/gained passively if no member died within a specified (long) timeframe, and was lost every time a faction member died for any reason.
How about implementing such a system to SE? It would deal both with the problem of bypassing base defences easily by mining around/destroying selected armor blocks for dead angling turrets, and the problem of there being no punishment whatsoever for dying in SURVIVAL mode (come on - people are casually using suicide to fast travel, you even get free tools every time you respawn lol)
Add a block the size of jump drive - big grids only, active only when the grid is stationary. Make it resource expensive (superconductors, grav components) and PCU-heavy (1k PCU e.g.). The block would let the grid to emit a field of invulnerability, so that no voxel can be destroyed (but blocks can be ground down with hand grinder) and no block can be placed by faction other than the owners. Make the field volume rely on faction strength tied to faction members survivalability and combat effectiveness as described above (with upper limit to said volume of course). Balance faction strength system so that it's zero sum system to prevent faction strength farming. Add incremental spawn time penalties for negative faction strength to deal with griefers/people using alts to drain turrets.
That system would deal with two major issues the PVP multiplayer is suffering now and add an incentive to actually care about defence grid layout.