External Flash for FUOTA with SAM R34


I am new to LoRa FUOTA and want to implement FUOTA in my SAM R34 based end node
SAM R34 has an internal memory of 256kB, so I am assuming that the maximum application size is 256kB for SAM R34 and we can use an external flash of 500kB for performing FUOTA.

So can I go with a 500kB external flash?
Does it cause any problem for FUOTA implementation