Getting multiple values against unique names...

The steps to tidy the formula up are insanely complicated for such a simple task (or maybe it's just me getting senile!).  To use any built-in function within a helper function, the built-in function needs to be wrapped as a Lambda function.

That is OK, 

Filterλ 
= LAMBDA(arr, crit,
     LAMBDA(acc,n,
         VSTACK(acc, TRANSPOSE(FILTER(arr, crit=n)))
     )
  );

but the presence of VSTACK suggests that all is not well.  Next, the REDUCE element of the formula needs to be wrapped in a further Lambda function to hide the complexity.  The intent of the REDUCE/VSTACK combination is to perform a MAP operation without triggering the 'nested arrays' error.  The worksheet formula is now

Mapλ
= LAMBDA(name, Fnλ,
    REDUCE(hdr, name, Fnλ)
);

The other trick is that the partially satisfied Filterλ Lambda function (itself a Lambda function is passed as a parameter to Mapλ, giving a final form for the worksheet function, 

= LET(
     array, Mapλ(UNIQUE(Table1[Name]), Filterλ(Table1[Value], Table1[Name])),
     IFERROR(DROP(array,1),"")
  )

which is far more complicated than it should be.