I've booked a classic emirates reward ticket for one person in F, BRU-DXB-BKK. 141k miles.

The BRU-DXB segment is on the new 777, unfortunately the DXB-BKK segment is on the old 777.

There is an a380 DXB-BKK flight that leaves less than an hour after the flight I'm confirmed on.

I'd really really really prefer to be on the 380 that leaves later.

There currently isn't an award ticket in F on that a380 flight.

What's the best way for me to get into F on the later a380 flight?

Can I waitlist on the later flight even though i have a confirmed reservation on the same day?

Should/can I change the DXB-BKK that I'm confirmed on in F and switch to business (which is available) on the 380, and then hope to upgrade to first at checkin in BRU? Or would I have to wait until I get to Dubai to check for an upgrade?

Or can/will they just change my flight from the old 777 to the later 380 if I ask nicely, even if there isn't award available in F?

Thanks.