>>720195242
In Delta, you can basically savescum auto saves and you can play New Game+ from any difficulty to any other difficulty, so you can bring back all the camos and items.
I just finished a playthrough on PC last week and you have plenty of time, even for some backtracking.
MK22 suppressors become non issue after the Pain fight, since you can get suppressor in the optional area where you get SVD, the warehouse after the part where you can kill The End, and there's another suppressor on the 2nd floor of Graniny Gorki lab. And all of these respawn after you get a cutscene with Granin.
After some boss fights it's worth backtracing to get some MK22 ammo.
Just make sure to bring something poisonous or spoiled for The Fear.
I might be wrong, but Ocelot and Volgin 1 can be beaten lethal.
If you caught all the GAKOs, the new item is basically octocamo with 95% camo index, and it doesn't even count as special item, so you can basically cheat everything that isn't boss fight or prison escape.