Can I upgrade the AMEX Velocity Platinum free flight to business?

Can I upgrade the AMEX Velocity Platinum free flight to business?

I'd like to use my free flight, but I'd also like to upgrade to business, even if some cash is involved. eg: Pay to upgrade to flexi, then use points to upgrade to business. Has anyone tried this?

They're booked as non-points earning "saver" fares. By the time you pay the change fee and the difference between the original fare and the flexi price you might as well just buy a flexi and upgrade from that - plus you get points and SC on the whole lot.