I know this is a bit screwy and takes a couple more cycles but
var item := CreateItemDescriptor(objtype);
item.CProps.NoStack := 1;
item := CreateItemInBackpack(of_character, item, amount := 1);
EraseObjProperty(item, "NoStack");
Just a note that CreateItemDescriptor is in POLSYS not UO.
CreateItemDescriptor was made for us to manipulate items before creation so we can create them straight into the stack instead of individually but of course this could be used the other way too

gotta love double-sided features
