customize soldier init with any weapon and attachments (that are not listed as options in the cfgweapons combinations (i.e. not srifle_lrr_sos_f but instead srifle_lrr_f w/optic_dms attached))
create trigger with delay of 1 second or more with on action:
soldierOne action ["DropWeapon", unitBackpack soldierOne, currentWeapon soldierOne];