Yes, you are right. You will need to check the Interupt Status Register status before you proceed for the next write command.
I am not asking about the ISR. I am referring to the write enable in a flash memory device that must be set before performing a write or erase to that device. The rsu1.tcl script pointed to in the document you link to (https://www.intel.com/content/dam/altera-www/global/en_US/others/support/devices/configuration/rsu1....) does not seem to send the write enable command, hence my original question.
Thank you for clarifying that, I'm sorry I misunderstood your first answer. Is it also true for the QSPI_WRITE_DEVICE_REG command?