Hi @zjhon.1 (Community Member)
the NFC Forum Activity specifications defines Card Emulation for TA4, T4B and T3 types. Our rfal_nfc convenience layer implement the card emulation for those types as defined by the NFC Forum.
If I well understand you need, you would like to emulate something close to T2 with additional proprietary commands. In my understand is correction, I would suggest to follow the recommendation provided by Ulysses HERNIOSUS to hack the T4T Card Emulation case in rfal_nfc.
Feel free to provide more information about your application and your use cases.
Rgds
BT
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