IMO

I'd like to check if this has worked on anyone -- how does it look? 
My goal is to create a schedule where day 1 to day 3 are the tabs, and the content of each tab is that day's schedule (where a portion can be expanded via accordion e.g. 1-3pm only because there are multiple, consecutive mini-events within that hour).

Thank you all for your help and attention!

Hi @tuanphan! Not yet -- I got the Accordion-Tabs Plugin from SqSp Themes (not the one from @WillMyers) but I cannot seem to use it to achieve what I want to do. I've reached out but no response yet.

Hi @WillMyers! Would your plugins be able to resolve this? 

Thank you both! 

Try this
div#block-yui_3_17_2_1_1599698725699_50131 .image-card { background-image: url(https://cdn.pixabay.com/photo/2020/12/14/11/18/cat-5830643__340.jpg); background-repeat: no-repeat; background-size: cover; }