"what about double meanings like in ππ₯¦ and π?" - Ah yes, these ambiguities are very famous. In order to get a new emoji approved nowadays, it's even helpful to be able to point out additional meanings and usages that are metaphorical in this way. The Unicode consortium is wary of introducing too many new emojis, and so those that can "carry more weight" and fill many needs at once are preferred.
In internet corpora the vegetable-related uses of these emojis are probably quite rare (but I must admit I haven't checked yet) - and the metaphorical meanings probably dominate. Though there are also many insider uses of emojis that aren't super widely known outside of their circle. This is comparable to other kinds of linguistic codes or innovations (e.g. in youth language) and not limited to only emojis. #WorldEmojiDay #emojis #linguistics