ilib, are you sure that Bitpay doesn't accept RBF-enabled transactions?
There is no logical reason for that, and they do not accept zero confirmation transactions.
The feature of not activating RBF is always found in casinos, as they try to speed up the deposit process so that the transaction is accepted with zero confirmations and wait for withdrawal after confirmation, and thus the user experience is fast, for the success of this, the transaction must not support RBF.
In the case of Bitpay, and because the service is a payment gateway, you must obtain one confirmation before doing anything, so using RBF will not change anything.
@ilib Bitpay has a history of shady activities try using an alternative company.