Hi guys,
My apologies for the long delay in replying. I was away for health reasons and am slowly transitioning back into normality.
@walterpre & @BigEyetuna The problem with the SST26 series is top priority and I will try and get this sorted within a week and keep you posted here.
@siva_iot I find that WDT reset usually happens when your code does not allow the ESP8266 to carry out essential background functions. make sure you have enough delay() statements at the right places in your code. the delay() function in the ESP8266 is different to the normal one used for ATmega or ARM boards and lets background processes run while waiting for user code to execute.
@jaholmes The simplest way would be to use the built in readByteArray()/writeByteArray() or readCharArray()/writeCharArray() functions. They let you define the size of the block of data you want read/written - sequentially - and are very fast.