Smartmatch ~~ and given/when are definitely experimental features in that it is still possible they will undergo radical changes, there is discussion on P5P about this from time to time. In other words, by using them, it's very possible your code will not be future proof. I would strongly recommend staying away from them. Luckily, there are lots of alternatives, see the replies in these threads:

In reply to Re: smartmatch with multiple search values by haukex
in thread smartmatch with multiple search values by toohoo

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