Bug #33023 (with commit e622555)has been partially fixed: few others Spring form tags (such as <form:select> and <form:options>) are still ignoring response character encoding.
Examples:
<%-- Select items as List --%>
<form:select path="p" items='${["café", "café crème"]}' />
<%-- Select items as Map --%>
<form:select path="p" items='<%= java.util.Map.of("café", "café au lait") %>' />
<%-- Options items as Map --%>
<form:select path="p">
<form:options items='<%= java.util.Map.of("café", "café au lait") %>' />
</form:select>