I have noticed than when using "Emojis as PNG-Image" rather than actual Text the Y alignment is different. I.e. the "Emoji as Text" is placed higher than the PNG counterpart.
Hence there should be a Y alignment option (like in Css the top / bottom attribute on position absolute for example).
Following Image shows that "Emoji as Text" are placed higher than the image itself.
"Emoji as PNG-Images" taken from here:
My settings ->