After looking all over the internet and trying a lot of these options, the only way to make sure that it is covered correctly with support for i.e is through javascript, i created a loop function to go over post items that require multi line truncation.
*note i used Jquery, and requires your post__items class to have a fixed max-height.
// loop over post items
$('.post__items').each(function(){
var textArray = $(this).text().split(' ');
while($(this).prop('scrollHeight') > $(this).prop('offsetHeight')) {
textArray.pop();
$(this).text(textArray.join(' ') + '...');
}
});