Wider/sharp rimmed (9 speed+) discs are much more influenced by the dome/flatness. The faster the mold, the more the profile (dome/flatness, PLH, and lower rim geometry) matters.
high dome/high plh = glidey & more overstable finish
low dome/high plh = no glide & dumpy finish
low dome/low plh = lower stability for the full flight
high dome/low plh = glidey & less stable finish
I would put Firebirds in with the slower fairway (6-8) and blunt edged discs (5 and below) in terms of how the profile affects the flight. Flatter are faster but lower glide than those with dome. Plastic blend & stiffness are better indicators of stability within the same mold. How blunt the leading edge is will determine the general stability compared to other molds.