Hi Chris,
The protocol is theoretically capable of transporting 64ch of bidirectional audio at 48kHz. However on GLD there are channel mapping limitations – the count of 64 dSNAKE I/O includes both the Main dSNAKE device and any local or remote Expander, so for example AR2412+AB168+AR84 = 24 physical outputs + 40 Monitor outputs (ME-1) = 64 out total.
At the moment we are not planning an AES3 version of GLD AudioRacks, but there are third party Dante or MADI to AES3 converters on the market that you might want to look at.
Hope this helps.