Using full Firebeetle ESP32-E flash in Platformio

Hi,
I have the DRF1139 ESP32-E modules, which have 16MByte flash, and have been successfully using them in Platformio using default 4Mbyte settings.

I now need more SPIFFS space, so have been trying to use alternate partition tables such as the default 16MB csv from
https://github.com/espressif/arduino-esp32/tree/master/tools/partitions

Although upload seems to work, and the ESP32Connect tool seems to show the new partitions have been established, the ESP32 goes into continuous reboots.
 

I have successfully run a non-4MB Blink sketch in Arduino IDE.
 

My guess is that PlatformIO still thinks there is only 4Mbyte of Flash.
In Platformio's list of available boards, there is only one option for DFRobot Firebeetle 2 ESP32-E, and it is 4MB.
I have been unable for find a platformio option to change this.

My board config:

[env:dfrobot_firebeetle2_esp32e]

platform = espressif32

board = dfrobot_firebeetle2_esp32e

board_build.mcu = esp32

board_build.f_cpu = 240000000L

framework = arduino

Any assistance would be appreciated, thanks.
Rob