If you make this small change then the formula will return even single values

=INDEX(E$2:E$1000,MODE(IF(R$2:R$1000=T$2&T$3,IF(E$2:E$1000<>"",IF(COUNTIF(T$3:T3,E$2:E$1000)=0, MATCH(E$2:E$1000,E$2:E$1000,0)*{1,1})))))

still confirmed with CTRL+SHIFT+ENTER