> TypeError: $(...).forEach is not a function

And so it starts. jQuery uses .each, not .forEach. So you fix that. But stuff still doesn't work.

Right, because jQuery's .each passes the index as first parameter and the element as second (or this).

jQuery trips me every single time.

document.querySelectorAll('.tpm_sensors').forEach((sensor) => {if (sensor.pressure < threshold) { fixBeforeIDie(); }});

Then this breaks in older browsers because forEach isn't a method on a NodeList. So you have to polyfill in features to do [...document.querySelectorAll('.tpm_sensors')].forEach(...);

and you usually define $ and $$ as querySelector and querySelectorAll at the beginning of the file if you don't like writing them all out, so they're exactly the same length

I remember the mess that came before jQuery. This is quite literally what we did back then, just with a custom made snippet of JS for finding by id and by class. It sucked. I mean to me Bootstrap is just a black box library, I don’t care how it works as long as it does. But this is going to suck for those working on its code.

No need to load a slow bloated library. Learn modern DOM methods. Reading does wonders, my opinion.