4 days in Okinawa in late October – Ishigaki or Miyakojima… or split 2 and 2?

Hey everyone,
We’ll have 4 full days in Okinawa around the third week of October (not counting travel days: we fly in from Tokyo and then out to Fukuoka).

We’re debating whether it’s better to:

• Spend all 4 days on one island (either Ishigaki or Miyakojima) and really enjoy it without rushing,
• Or split the trip: do 2 full days in Ishigaki, then take an early morning flight (about 30 mins) to Miyakojima and spend the last 2 days there.

What would you recommend? Which island has the better beaches/food that time of year? And is it worth splitting such a short stay, or better to just settle in one?

Thanks a lot!