The proposition that representations in relation to a s 501 cancellation attempt are not ‘mandatory relevant considerations’ is highly doubtful if not at least reductionist. See the discussion in Viane v Minister  FCAFC 116 per Rangiah J - and Colvin J at -. What matters is (or perhaps a better characterisation than ‘mandatory relevant consideration’ is) whether the relevant aspect which was not considered could amount to a ‘representation’, in which case it must be considered.
See also Hay v Minister  FCAFC 149 per Colvin J.
As to what is required to show that there has been a consideration, see Minister for Immigration and Border Protection v Maioha  FCAFC 216 at :
What is required is the reality of consideration by the decision-maker. On judicial review the Court must therefore assess, in a qualitative way, whether the decision-maker has as a matter of substance had regard to the representations put: compare Fraser v Minister for Immigration and Border Protection  FCA 1333 at  per Perram J. Additional adjectives do not assist that analysis and indeed tend to distract from it by being “apt to encourage a slide into impermissible merit review”: Minister for Immigration and Citizenship v SZJSS  HCA 48; 243 CLR 164 at  citing Swift v SAS Trustee Corporation  NSWCA 182; 6 ASTLR 339 at . Because the Court must make its own qualitative assessment, the fact that a decision-maker says they have had regard to a representation does not by itself establish that they have, as a matter of substance, had that regard. Neither does the Court ignore such a statement.