I think this heat issue may effect high frequencies most.
And it may be that the AG sold, “Deulund-Mundorf Ultra Speaker Purifiers” could be the solution to the heat issue. After 100++ hours of breakin they have had a profound effect on the soundstage and imaging. I now hear layers in a wide and deep soundstage and imaging has come into focus like never before.
These can be self made but the seller adjusts the values of the cap and resistor to match your speaker’s needs.
This idea is not new. They are also known as Zobel Networks.
They only effect frequencies 12K and above. So above the crossover point of most.
Radically improved my listening experience.