Currently, SHA256E creates duplicate files for different extensions, i.e.:

$ l * && l -Li * && sha256sum *
lrwxrwxrwx 1 atemu users 198 2021-05-04 03:47 random.1 -> .git/annex/objects/F9/Kk/SHA256E-s104857600--2fdbdc9c3b23d1986a743aede593765e57ade9f173f9fd9766057f0efd63197a.1/SHA256E-s104857600--2fdbdc9c3b23d1986a743aede593765e57ade9f173f9fd9766057f0efd63197a.1
lrwxrwxrwx 1 atemu users 198 2021-05-05 10:01 random.2 -> .git/annex/objects/Pm/J1/SHA256E-s104857600--2fdbdc9c3b23d1986a743aede593765e57ade9f173f9fd9766057f0efd63197a.2/SHA256E-s104857600--2fdbdc9c3b23d1986a743aede593765e57ade9f173f9fd9766057f0efd63197a.2
 3720 -r--r--r-- 1 atemu users 100M 2021-05-04 03:47 random.1
49696 -r--r--r-- 1 atemu users 100M 2021-05-05 10:01 random.2
2fdbdc9c3b23d1986a743aede593765e57ade9f173f9fd9766057f0efd63197a  random.1
2fdbdc9c3b23d1986a743aede593765e57ade9f173f9fd9766057f0efd63197a  random.2

These have the exact same content though, they could be hardlinks of one another instead and nothing would change.