I wouldn't worry about cage furnishings personally, esp in this rush situation.
The most would be down the line, a hide maybe but not needed.
My ex and his dad house a large burm that was rescued from a pet store fire, lots of vet visits for the smoke damage but he pulled through. It sounds like these people got the snake out quickly so *knock on wood* it should be okay.
I just hate uline as they are competition for the company I work for XD
Anyways, I use single face corrugated for all my adult boas as it gives a lot more traction than flat paper.
Since I no longer work in the office and can get at cost (since before the pandemic) - I buy it on amazon. A vendor I like to use is tape logic. It's usually $50-60 for the 250' roll with free shipping.
I prefer B flute as the 'waves' are larger but A flute works as well and is cheaper
here's a few links:
https://www.amazon.com/dp/B075TZ7D5X...v_ov_lig_dp_it
https://www.amazon.com/dp/B01N6F5GS3...v_ov_lig_dp_it
good luck!