as of v4.11 there are 4 additional filters you could use to add html before/after/inside each ingredient that is available for selection like so :

if you wanted to add additional li’s before or after a particular (or all) ingredients li’s

filter: wppizza_filter_ingredient_li_pre
filter: wppizza_filter_ingredient_li_post

example usage:

/*add before li**/
add_filter('wppizza_filter_ingredient_li_pre','my_wppizza_filter_ingredient_add_li', 10 , 10);	
/*add after li**/
add_filter('wppizza_filter_ingredient_li_post','my_wppizza_filter_ingredient_add_li', 10 , 10);
function my_wppizza_filter_ingredient_add_li($markup, $item_id, $tier_id, $size_id, $ingredient_id , $ingredient_price , $parts_id, $multiset_id, $custom_group_id, $custom_group_type){
/**if required add conditionals by available parameters*/
$markup.='<li style="display:block;width:100%;clear:both;background-color:#cecece">something before or after</li>';
return $markup;
}

if you wanted to add additional output INSIDE ingredients li’s

filter: wppizza_filter_ingredient_li_inner_prepend
filter: wppizza_filter_ingredient_li_inner_append

example usage:

/*directly after the opening li*/
add_filter('wppizza_filter_ingredient_li_inner_prepend','my_wppizza_filter_ingredient_in_li', 10 , 10);	
/*directly before closing li*/
add_filter('wppizza_filter_ingredient_li_inner_append','my_wppizza_filter_ingredient_in_li', 10 , 10);	
function my_wppizza_filter_ingredient_in_li($markup, $item_id, $tier_id, $size_id, $ingredient_id , $ingredient_price , $parts_id, $multiset_id, $custom_group_id, $custom_group_type){
/**if required add conditionals by available parameters*/
$markup.='<span>something at beginning or end of ingredeinst li</span>';
return $markup;
}

Note: the above will not work on ingredients custom groups that are set to use dropdowns instead of radio buttons as these are not wrapped in list tags