Load into the editor, then paste this into the script console:
player enableStamina true;
{player addWeapon _x;} forEach ["launch_RPG32_F","hgun_Pistol_heavy_01_F","MMG_01_hex_F"];
player addSecondaryWeaponItem "RPG32_HE_F";
{player addPrimaryWeaponItem _x;} forEach ["muzzle_snds_93mmg","acc_pointer_IR","optic_tws","bipod_01_F_blk","150Rnd_93x64_Mag"];
player forceAddUniform "U_I_Protagonist_VR";
player addVest "V_PlateCarrierSpec_rgr";
player addBackpack "B_Carryall_oli";
systemChat format['player canAdd "150Rnd_93x64_Mag": %1 | isStaminaEnabled: %2',player canAdd "150Rnd_93x64_Mag",isStaminaEnabled player];
player enableStamina false;
systemChat "Stamina disabled";
systemChat format['player canAdd "150Rnd_93x64_Mag": %1 | isStaminaEnabled: %2',player canAdd "150Rnd_93x64_Mag",isStaminaEnabled player];
player addItem "150Rnd_93x64_Mag";
systemChat "Added magazine";
In chat, it will say you can't add the Navid ammo both times (With stamina enabled and disabled), even though you have plenty of inventory space, and the stamina system is disabled.