That combination is how it already works. You can build combined "characters" (grapheme clusters) from multiple code points, e.g. you could have a "base emoji"

That combination is how it already works. You can build combined "characters" (grapheme clusters) from multiple code points, e.g. you could have a "base emoji" followed by a "modifier" emoji, and AFAIK that's how emojis with different skin colors work (one code point for the base emoji (e.g. 'thumbs up'), and a number of skin color modification code points which can be applied to all emojis that involve skin color.