Hi @peekay123 what you say makes sense to me but it seems to conflict with @mdma comment
from this other thread Implications of customized system firmware - Photon - #8 by HardWater where similar issues were discussed.
I did a search for the source for dct_read_app_data & dct_write_app_data but cannot find it in the repo only that it is defined as an extern function. I was thinking that maybe there are lower level commands that I need to execute to access the hardware and those commands were accessable.