Does ChargeBee perform any card verification or checks during checkout to ensure customer's do not sign up with incorrect credit card details?
When passing the name to the payment gateway, we merge the first name and last name contents and send it, and so a transaction would not be effected no matter how the customer fills in their name in the provided fields. You could disable the 'last name' field (from under Settings > Field configurations > Card information) and rename the 'first name' field as "Name as appear on card" (from under Settings > Text configurations > Card) in the web interface. This would allow the customers to enter the full name in a single field, but however First/Last name fields would not appear along with it.
Here's a screenshot for your reference:
At the moment, we do not have a default "Name as appear on card" field in Chargebee and I've added your recommendation as a feature request for our engineering team to consider.