I have a strong data point to report.

$10+ MUST be charged to the Chase Visa (Quest in my case) to achieve the TravelBank+Quest Combo.

e.g. $197.96 Airfare
Tried $0.96, $1.96, $5.00, $9.99 ALL get auto declined, but chase sees nothing on their end.
Spent more than 1 hr with UA Chat, ZERO help, just madness.
Finally tried $10.00 Chase Visa + 187.96 TB (Approved)

Added notes. This fare is for 4 people. The TB credit is from my quest card. The agent(s) confirmed I will not get bags without the Chase Quest. BUT in the past I have firmly argued my point and the CIA allowed me to proceed.

Most annoyingly, I probably could have just done carry on for this short trip, but I didn't want to risk having to pay 35*4, hopefully this can help someone save time.