I'm wanting to write a few bytes to the SRAM via NFC on the NTAG I2C plus NT3H2211 device, and was wondering if this can this be done in SRAM mirror mode or is this only possible in pass through mode?
It depends on what you want to achieve. Long story short:
-> If you mirror SRAM to EEPROM, mirrored part can be a part of NDEF msg (NDEF is always in the beginning of user memory) so you can read out SRAM value with NFC Mobile, without app needed.
-> But if you use SRAM in normal location (no mirroring), then you use it for pass-through mode more likely, then you need an App - because you need to tell SW (App) where to write.
In conclusion, if you plan to be writing raw data to the SRAM directly from the Smartphone, use pass-through mode.
Retrieving data ...