It didn’t overload the CPU

It did.
Not as much as steem.supply and some other websites unrelated to STEEM that I know, but it did.
We may regard the word overload in different ways.
I did not mean that it clogged it completely like some of those websites.

and it’s certainly not mining cryptocurrency, it was just inefficient and needed a refactor.

I saw your acknowledgement of the inefficiency in your initial post, and added another suggestion for improvement in my comment after I edited it.

JS is evil.
I try to avoid JS demanding websites as much as possible.
I will try your website again, but compulsory JS is always bad.
My suggestion in my previous comment applies to other real time needs as well.