On non-Spechtian varieties

This article is devoted to construction of infinitely based series of identities. Such counterexamples in Specht problem are built in any positive characteristics. The main result is the following:
Theorem. Let $F$ be any field of characteristic $p$, $q=p^s$, $s>1$. Then the polynomials $R_n$:
$$ R_n=[[E,T],T]\prod_{i=1}^n Q(x_i,y_i) ([T,[T,F]][[E,T],T])^{q-1}[T,[T,F]], $$
where $Q(x,y)=x^{p-1}y^{p-1}[x,y]$, generate an infinitely based variety.