The following changes have been implemented:

>modified brushwork and clipping to alter layout and sightlines
>modified train logic for efficiency
>added doors to spawn rooms
>added warning lights for trains
>modified health & ammo placement
>reworked left-hand flank to point, it's now more spacious and has a water element
>reworked train speed & timing
>added cubemaps and spectator cameras

To do:

>add ambient soundscapes
>ensure train is bug and exploit free
>fine detailing
>playtesting