Would it be possible to have it so a header value changes when order bump is selected.
I want to customize the subtotal, total text outside of the order summary element.
Unless its possible to edit and add elements to the order summary element itself. Ex. Bolding/editing price, adding additional values.
Hey @Flip 
Welcome to the community!
Yes, it’s definitely possible to customize the subtotal or total based on the order bump toggle using JavaScript. You can also react to the changes and update elements outside the order summary area.
Before I share a working snippet, do you happen to have a reference or example (like a screenshot, URL, or design) of what you’re trying to achieve? That’ll help me guide you more precisely — whether you’re looking to bold prices, add extra values, or fully customize the order summary.
Looking forward to helping you out! 