There is absolutely no reason why Cummings should be at a SAGE meeting, apart from as an observer, perhaps.
From the article:
"Former chief scientific adviser, Sir David King, said he was shocked to discover there were political advisers on Sage."
"David Liddington .... de facto deputy to Theresa May .... said 'I'm not aware of any minister or special adviser, ...., ever having been involved in the scientific advisory panels..."
"Other Sage participants told the Guardian that the Downing Street afvisers were not merely observing the advisory meetings but were actively participating is discussions about the formulation of advice"
Cummings is not a scientist. Repeat; not a scientist. He has no place on the panel. Nor any right to be formulating scientific advice.
I really don't think that some tory supporters have any idea about what is and is not appropriate for Cummings to have involvement in.
Bloody Boris shouldn't be there, either.