Request: Alias for multi-dimensional sets

In current GAMS versions we can only use ALIAS on single dimensional sets. However it would be an obvious improvement to relax this restriction. Here is an example where I needed an extra set to handle a simple mapping:

set mapper(*,j) /
  x1 . const
  x2 . Z1
  x3 . Z2
  x4 . Z3
  x5 . Z4
  x6 . Z5
  x7 . Z6
  x8 . Z7
  x9 . Z8
/;
 
* we cannot alias 2 dimensional set so we create two
set mapper2(*,j);
mapper2(mapper)=yes;
 
h0(j,jj) = sum((mapper(hi,j),mapper2(hj,jj)), h('e1',hi,hj)); 

It would be logical to use something like:

alias(mapper,mapper2);