While there's always a possibility of doing that, it is a bit too impractical. The BGA memory chips would have to be the exact same pin out and voltage requirements. Then we'd have to make sure that the entire memory is addressable and not conflict with other peripherals (speculating, maybe possible if there's some slack, and with ML). Even if we could theoretically increase the Memory, it would only minimally increase recording time because the buffer offloading speed to cards would have to be fast enough.