How to use AES correctly in BPS Format Preserving Encryption
AES is directly used as a block cipher without a mode of operation in BC / BPS. 

This would be identical to ECB mode for one block or CBC mode for one block and a zero IV in the case that the block cipher itself is not directly available. In that case you should not pad or remove a full block of padding if padding cannot be avoided. CTR of one block with a zero IV/nonce would also work.

But basically the answer to "what modes are acceptable" is: none. In that case the IV is also not applicable. The tweak can be seen as a specific kind of IV. Likewise you could see BC itself as a mode of operation for the block cipher.