currently it is set to 10 - we plan to increase that, but this is currently bound to the internally available flash-space of the MCUs. Moving them to external memory would be an option, but then these won't be available through NFC. The next step will likely be to increase the available resident keys to something like 20 with some optimizations on storage size - supporting more will likely require moving into external memory and thus not having them available for NFC operations - we'll have to define how exactly we'll do this without loosing NFC capabilities for FIDO2 overall...