It looks I solved it...
For me it looks there is no other, but to add htmlFilter rules.
Did it like this:
CKEDITOR.on('instanceReady', function (ev) {
ev.editor.dataProcessor.htmlFilter.addRules(
{
elements:
{
$: function (element) {
if (element.name == 'a') {
if (element.children.length == 1) {
if (element.children[0].name == 'span') {
var innerSpan = element.children[0];
if (innerSpan.attributes.style) {
element.attributes.style = innerSpan.attributes.style;
}
}
}
}
It checks if link contains only one span children and when just copies everything in style attribute.