Where to start to add external storage to Electron

Thanks again, @peekay123. SPIFFS looks promising; I’ll give that a shot. Though when I begin importing extra libraries like that, do I have to start using my own toolchain to build/compile projects?

I’m reading this thread (Suggestions for using external flash SPI) which looks particularly beneficial for my application. From your post here, it looks like SDFat still has some major advantages. If you happen across any surface mount components that work with SDFat, I’d love to learn about them.

Ultimately, I’ll want to be able to write around 100 MB (maybe more but I’ll stop there for now to keep things inline with SPIFFS capabilities) to some chip during an underwater deployment, then do some post-processing on the Electron then send post-processed data via cellular.

Do you think that Electron (or, perhaps, the incoming e-series) is well suited for this sort of application?

Thank you!