I guess sealing the gap between cone and frame is also a good thing, particularly for air suspension speakers where the compressed air in the cabinet is used to control cone excursion at resonance rather than "back pressure" from a tuned port.

M60ti, VP180, QS8, M2ti, EP500, PC-Plus 20-39
M5HP, M40ti, Sierra-1
LFR1100 active, ADA1500-4 and -8