  The paper considers some new properties of the so-called $A$-maximal
numerical range of operators, denoted by $W_{\max}^A(\cdot)$, where $A$ is a
positive bounded linear operator acting on a complex Hilbert space
$\mathcal{H}$. Some characterizations of $A$-normaloid operators are also
given. In particular, we extend a recent recent by Spitkovsky in [Oper.
Matrices, 13, 3(2019)]. Namely, it is shown that an $A$-bounded linear operator
$T$ acting on $\mathcal{H}$ is $A$-normaloid if and only if $W_{\max}^A(T)\cap
\partial W_A(T)\neq\varnothing$. Here $\partial W_A(T)$ stands for the boundary
of $A$-numerical range of $T$. Some new $A$-numerical radius inequalities
generalizing and improving earlier well-known results are also given.
