Most studios include one or more multichannel audio interfaces with many devices routed to the DAW.
Mixers, Audio Interfaces, ADAT interfaces - all of them have connected devices. Ity is often difficult to remember what ports of these devices are assigned in order for proper input and output to/from the DAW.
REASON as a DAW - includes its own good familiar HARDWARE INTERFACE. 16 audio I/O by default.
We still need to remember what instruments or effects are connected to the I/O ports of the audio interface and also how channels of the interface are routed to the Reason Hardware I/O.
Some musicians (producers / engineers) physically mark the names of used devices on their hardware rack (with stickers or tape) along with Audio Interface I/O and DAW channel info. This is a nice solution for Gigs and studio work.