I removed a banana that was in ground about two years as it proved to be just too big. I planted it unceremoniously in a moist sandy spot deviod of life, and after removal it left behind a big surprise, some really nice dark sandy soil full of worms and other slithering insects.
I've removed bananas before and don't recall this side benefit.
Anyway, the mat I removed is about 3' round and over a foot deep. I plan on allowing the pstems and leaves to decompose where they fell but in the past after removing bananas I dumped the mat out with bulk trash. I'm thinking this time to hack up the mat and let it decompose on the surface of the ground also. Other than the possibility of some roots taking hold in the soil as a watch item, might there any benefit to leaving the mat also?