SelfBoot SPI EEPROM flashing via I2C

Hello,

I have an ADAU1467 eval. board with 25AA1024 SPI EEPROM connected via USBi to SigmaStudio 4.6 (rev 1812)
Everything works fine while Hardware Configuration USB is set to SPI (SPI 0x1 ADDR0)
So I can write a program to ADAU1467 directly, also can “write latest compilation through DSP” (with SelfBoot switched temporarily off on the board) and have the same program running after Reset/Restart.

However if I switch the connection from SPI (SPI 0x1 ADDR0) to I2C (I2C 0x76 (118)) I can only update the program in the processor successfully, but can’t write the compilation to EEPROM.
Obviously I switch SelfBoot off before performing “write latest compilation through DSP” (as in the “SPI mode”), the writing finishes without errors. but after switching  SelfBoot back on and Resetting the board, the processor boots old program (previous EEPROM content)

I realize that “write latest compilation through DSP” means loading a “flashing stub” into the processor first. Unfortunately I can’t find any details about the stub capabilities, i.e. whether the stub can write to (master) SPI connected EEPROM from (slave) I2C.
The I2C connectivity itself works fine though. So the program can be written to the processor, but never to the EEPROM.

I tried to tweak Multipurpose1/Secondary I2C (just in case) – no effect,
tried to add/remove/configure EEPROM in HarwareConfigiration/Config – no effect. The problem remains.

While connected via SPI I had  USBi’s “SPI 0x1 ADDR0” connected to ADAU1467 and “SPI 0x1 ADDR0” connected to E2Prom (the latter looks redundant for a reason)
While using I2C I have USBi’s I2C 0x76 (118) connected to ADAU1467, but can’t choose the same for E2Prom (SigmaStudio doesn’t allow to choose the same I2C address), so I tried different I2C addresses, but without any EEPROM flashing effect. The program can be written to the processor directly though.

So the questions, if I might, whether SPI EEPROM programming is supported via USB/I2C and how it could be configured. I’m planning to use an MCU with I2C later to make the program changes available on autostart, so ability to change EEPROM would be very desired

Thank you,
Serge