How to avoid vertical scrollbars on Acuity Scheduling when using iframe embed (not scheduling block)

If you use a scheduling block, it calculates the height perfectly in all reponsive screen sizes. No scrollbars ever. 

When using the iframe embed, it doesn't work. In some pages like cart or order confirmation you cannot use scheduling block. I'm wondering if there's a way? 

video describing the issue

I'd hate to resurrect an old post, but I've been trying to figure this out for weeks and I've found nothing. It make's my site look so unprofessional, and it's nearly impossible to navigate on a phone.