Meta Craft and synth implicit rolling with vivid vulture

I put a cannot roll caster modifier on synth ring with a caster implicit(spell damage per power charge) it re rolled the caster implicir modifier but i put cannot roll attack and rolled a lot of rings like that and didnt see any attack mod implicits, so i think cannot roll attack and cannot roll caster prevents those mods to come but dosent effect rolling them to a new one is this intended?(item has two synth implicits)

metamod only works on explicit mod