Thank you for the quick and helpful replies.
(1) Do you know if this issue has been fixed in Android 10 and beyond? I could update my phones OS if really needed.
(2) Since my PC USB-based PC/SC reader (SCL011) does not recognize the demo cards as well (the manufacturer specifies support for ISO 14443, but not ISO 15693), would the Spark 2 be supported better on this reader as well? I would really like to use this or a similar USB reader, because I plan to integrate it into my laptop and since I already have it. I don’t think a Proxmark would fit, and it would also require a bit of software shenanigans to get working like I would want it to.
(3) Since both the spark 1 and the demo cards seem to use ISO 15693, is the Fidesmo card 2.0 a better development platform for the spark 2 considering that it uses ISO 14443-A as well (Taginfo reports ISO 7816-4, 14443-4A, 14443-3A and 14443-2A)? Sadly, the Vivokey app reports “NFC error” for the Fidesmo card as well. Could it be reflashed to present as a Vivokey? Could I use any ISO 14443-A javacard and flash it as a Vivokey?
(4) Also, regarding PC/SC and CCID in general: The Fidesmo card reads great as a CCID device, which enables me to develop and test applets comfortably using the USB reader. Is this possible for the Spark 2 / the Apex as well?
(5) Regarding the upcoming Apex line: Does the Apex use ISO 14443a as well? Is CCID / PCSC supported? I plan to replace my Yubikeys.
Sorry for the amount of questions, and thank you in advance for any answers.
P.S. Since Fidesmo does not offer a HMAC-SHA1 applet I managed to compile and deploy an open source implementation of the one used in the Yubikey. I’d like to do the same or use an existing compatible applet on the Vivokey platform.