8 hours, some longstanding issues.
The most recent attempt to stop a walker from getting so close to the player that it cannot be shot is redoing the colliders on the walker and making it such that if the player is in contact with the projectile collider, the walker is pushed away until such is no longer true.
Lurkers are no longer only spawned on the cardinal directions. With the power of random floats they can spawn anywhere.
Changed Lurk behavior to require the Lurk to be on screen for a certain amount of time before veer behavior triggering. This makes the Lurks both a little easier to hit when you catch them early in the approach, and more dangerous when you catch them late.
Walkers that are spawned by the stage progression are now spawned through the 'Spawn Occupier' function. Spawn occupier is now used to summon Walker Warp Effects. Walker warp effects, previously only a particle effect, now spawns the unit it heralds (much like the Turret Warp Effect). The walker warp effect occupies a space for 0.25 seconds. This creates enough of a buffer that we can not worry about walkers spawning on each other and we can stop checking for if the walkers should be telefragged (a weird mechanic, and one that would randomly benefit the player which isn't the thing we want to happen ever). All instances of single walkers being spawned are generated in this way.
All walker counts also count walker warp effects, and threat check cares about walker warp in effects.