Of the other Irish aces with an August connection:
Francis Dominic Casey
was killed on 10-Aug-1917;
Oscar Heron was killed in an air crash on 05-Aug-1933;
Forde Leathley died on 25-Aug-1982.
Eugene Owen Cruess Callaghan, brother of the ace Joseph C Callaghan, was killed on 27-Aug-1916.
Of the non-ace, plain vanilla Irish aviators with an August connection there'd be too many to mention, but here are a few from my spreadsheet with the surname beginning with 'B':
William Claud Kennedy Birch was born in India on 24-Aug-1891;
Gerard Lovell Backhouse was killed on 02-Aug-1916;
Joseph Bamford was killed on 20-Aug-1917;
Manchester-born Gerald Benedict Barre was killed on 09-Aug-1918;
Cecil Barry was killed on 21-Aug-1917;
William Beirne died of wounds on 18-Aug-1918;
Henry Boyd was killed on 25-Aug-1918;
Thomas Brownrigg was killed on 21-Aug-1918.
McElroy will always remain special though, as it's unlikely any aviator (let alone an Irish one) will ever get to achieve 7 aerial victories, not to mention 47).