"It’s also worth mentioning that most KaiOS devices have either 256MB or 512MB of RAM, which is often the most limiting resource."

From experience, I have about 8GB of podcasts, and would rather not change my habits that much.

You should be looking at how much storage the device has, not RAM.

Derp! Okay, the Nokia 8110 mentioned has 4GB of storage, with MicroSD up to 32 GB.