I think the MicroSD card below is suitable for mass storage.
But what I’m missing on the spec sheet of the Fairphone 4 is what the max speed of the card reader bus is. It only lists the max size and type. I can go full re$%rd with the most expensive SD card. But if the Fairphone can only read/write at suboptimal speeds, then it doesn’t matter to go for a fast SD card. Then I can go for a cheaper one with more storage.
Does anyone know more details about this? If not, then I’ll contact customer support of course.