ADM3053 has no minimum baud rate, because it has no "dominant timeout" (it won't bring CANH/CANL recessive even if TXD is still held low for a long time). The part will operate normally even at very low bit rates.
The EVAL-2LCANRS485EBZ may be a helpful example. Its a two port (CAN & RS485) board that demonstrates layout techniques with the ADM3053 and ADM2582E. This board meets Class A. Emissions scans are available in UG-1561.