Achtung Spitfire! Mission #5 - Fire on the Road slow down

[Badger343rd]

Having trouble with this mission slowing down(yet fps are high) I assume its something to do with frontline density but can't find the settings to change it. I'm thinking it was in the editor somewhere but I can't even find the mission file to open it...a folder in the campaign folder called "spitfire" is there , but no mission files are inside. How do I address this slow down issue ? Am I looking in the wrong place?