thanks for the clarification about the DRAM.
As I recall Soft error error due to radiation was a big research thing a few years back (R. C.Baumann, T.J. O'Gorman etc) but perhaps I got the wrong end of the stick.
With Flash I know you have to section erase but I thought you could write to individual bytes, but I take your point. I have always considered Flash as EEPROM
Back to being a musician.
All the best
Royce