What about p971?

P971 = EEPROM storage control 0 - 1
0 =   Changes to parameter settings (including P971) are lost when power is removed.
1 =   Changes to parameter settings are retained during periods when power is removed.

IMPORTANT:
When using the serial link to update the parameter set held in EEPROM, care must be taken not to exceed the maximum number of write cycles to this EEPROM - this is approximately 50,000 write
cycles. Exceeding this number of write cycles would result in corruption of the stored data and subsequent data loss. The number of read cycles are unlimited.