Wouldn't it be better to revise this page to remove all HTML/javascript/webtag related code. As the Feels Like is clearly well calculated and delivered by CumulusMX now, it is kind of confusing what you are trying to say here.
Giving the forumula, references and what and where to get it from Cumulus should be enough I think.
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I had already deleted the code relating to Feels Like in MX, for the very reasons you mention.
The code you must therefore be referring to was written for Cumulus 1, and it remains valid in that context.
There are plenty of people still using Cumulus 1, at latest estimate significantly more people use Cumulus 1 (various versions) than use MX which still has many bugs despite being out of Beta.