Forgot to mention that I'm using an Electron. Looking again at the memory map for modular firmware section of the Electron datasheet I noticed that the factory backup sector is labelled as "Factory Reset/Extended Application"... which makes me think that I should be able to do what I am suggesting....
Is this a limitation of the the Particle servers, spark firmware, bootloader, or the bare metal STM32 (or all 4?)
I understand that the OTA backup sector needs to be at least as big as the user application sector, but I don't understand why I wouldn't be able to increase both of those sector sizes by the same amount (i.e. 192 kB user application sector and 192 kB OTA backup sector).
Any solution to increase the size of my program would need to preserve the ability to send OTA updates, so the monolithic firmware build is not an option in my case.