Normality of elementary subgroup in $\operatorname{Sp}(2,A)$

Let $A$ be a ring with involution (associative, with identity), $e_1,\dots,e_n$ be a full system of hermitian idempotents in $A$ such that every $e_i$ generates $A$ as a two-sided ideal. This paper proves normality of the elementary subgroup in $\operatorname{Sp}(2,A)$ if $n\ge3$ and $A$ satisfies an analog of local stable rank condition.