Default

Multiple: $tree->{type}{default}{report}
Single:   $tree->{type}         {report}    Inconsistent


KeyAttr=>[]

Multiple: $tree->{type}[0]{report}
Single:   $tree->{type}   {report}          Inconsistent


ForceArray=>[qw( type )]

Multiple: $tree->{type}{default}{report}
Single:   $tree->{type}{default}{report}    Consistent


ForceArray=>[qw( type )], KeyAttr=>[]

Multiple: $tree->{type}[0]{report}
Single:   $tree->{type}[0]{report}          Consistent