Boarding and the hostile grinding speed modifier.
TLDR, reduce grind speed for unowned blocks instead of owned, to balance boarding.
Currently, if you attempt to grind a block owned by a hostile player, your grinder works more slowly than it would otherwise; grinding a door owned by an enemy takes longer than grinding a door owned by you. I can only assume this was to increase the challenge of boarding/capturing a ship.
This speed reduction is only against owned blocks, I.E. blocks with computers in them. Against enemy grids especially, it's significantly faster to grind through the wall next to a door than to go through the door itself.
When someone considers boarding a ship, the likely image in their head is one of armed engineers fighting through corridors to secure the interior of a ship. In my experience, however, boarding tends to simply be a mad dash past the ships exterior turrets (somewhat easy considering how agile suits are), followed by haphazard grinding of anything and everything they come across. It can be absurdly effective to simply respawn with basic tools and repeatedly rush a ship, at no cost to the attacker.
With the recent changes to infantry/suited combat, this will likely only get worse. Previously, interior turrets could kill a player in an instant, while now it takes a few seconds (an otherwise welcome change). Because of the low time to kill, interior turrets used to be very effective against a careless boarder inside a ship where they don't have room to rapidly maneuver; this is no longer the case. Additionally, with the addition of the rocket launcher, players can disable turrets more quickly, furthering the problem.
I suggest altering how the current grind speed multiplier is applied. Instead of slowing the grind speed for owned blocks on the grid, reduce the speed for all UNowned blocks, so that cutting through armor is more difficult than cutting through systems and doors. Walls and bulkheads would then serve as obstructions to boarders, and doors as bottlenecks. Encasing your systems would protect them from enemy assault, and structuring an interior would funnel boarding teams along specific paths.
This would of course make boarding more challenging, but I consider that a benefit. It could also serve to dampen the use of unlimited respawning to attack a ship, as players with only basic tools and no weapons would have a significantly harder time cutting through a ship. Finally, fighting through ships would provide a good use for the new infantry weapons, even at later stages of the game when players have the largest ships.