Is there a way to change the on/off text of a sensor as well as their respective on off icons without resorting to a sensor template? Eg. by setting an attribute icon_on icon_off text_on text_off ? I did not see this anywhere.
Device classes usually solve this. But you’d need to resort to a template binary_sensor anyways because sensors typically aren’t on/off. Binary_sensors are.
Side note, you can typically change all this in the front end depending on the lovelace card you are using.
I meant a binary sensor, my bad.
So imagine I have a Entity button card, I don’t immediately see how to customize this. Could you give an example of a card that does so?
take a look at the device_class settings. That will change the on/off names and the icon used so that the icon reflects the state.
You add this in the customization section or in the setup of the sensor itself (if possible).
If I understand it correctly, I am limited to the list that is give there? What if I want something different than is supported in that device_class list? 
then you’d need to make a template sensor or handle the translation & icon in the UI
OK, would it be sensible to make this a feature request to add customization attributes to a binary sensor? If you have a lot of binary sensors and have to make additional sensor template entities for each of them to be able to customize, that’s a lot of additional entities for just this purpose.
Yeah you can make a request. But you may just want to make a request to have whatever sensor you have added.
What is it?
Now that I think of it, it’s not sa much binary sensors I was thinking of but rather switches, currently they are toggle buttons, but when I add one on an entity card, it shows as a script icon, when I click on it, it doesn’t become ‘active’ (i.e. yellow icon).
you mean they show up as 2 lightning bolts?