Possible to use FlexDF just like the FlexNT just with way more storage space?
Well, yes and no… I mean, it is ISO14443A so on a hardware RF level, they both “speak the same language”… but there are like 3 other major levels from reader firmware to middleware to application layer… in short, no the NTAG216 chip in the flexNT is not just like the DESFire EV1 chip inside the flexDF.
If all you are going to use the flexDF for is storing NDEF data for use with smartphones, then yes it will basically work like a much larger capacity flexNT… but if you want to use it with access control systems or basically any other RFID application, then no… there are significant differences.
So I bought the df planning to use it for rfid type devices that may require a high frequency I can’t really use it for that?
I can’t tell you if it will work or not. It’s kinda like asking “I bought a screwdriver, can I use it to take things apart?” … some things yes, but other things require a different type or size of screwdriver.
In short, RFID is a “type” of technology, not a specific thing… there are so many aspects to it that simply matching frequency is only a fraction of properties describing an RFID system (system = tag+reader+software)