Hello @jdbrngr,
Great question!
I would first suggest reviewing how your event is structured to passing these various form of payment methods to Klaviyo. Doing so would allow you to see the metadata that is shared and also provide you with the appropriate syntax required to pull in a different set of tags which may return your desired result of highlighting the payment method as PayPal.You can find guidance on how to find your desired variable tags along with how to utilize these event data in your email from the About Using Event Variables to Personalize Flows Help Center article with a helpful video under the How to Find Event Variables subsection.
Since it seems like the variable you are currently using of {{ event.extra.payment_details.credit_card_company }} may be too specific for your use case of wanting to also highlight the payment method of being PayPal, I may suggest reviewing the data above this specific array item and see if the syntax will return your desired result.
Some other Community posts that may be helpful in reviewing are the ones below which touch upon a similar subject to what you were trying to accomplish:
I hope this helps!
David