I have a 2017 iMac with Thunderbolt 3. I also have a great FireWire 400 audio interface (Presonus). There are no other ports on the Presonus that'll connect to the iMac. Before sinking money into this, I need to know if this is what I need to purchase: Apple TB3 to TB2 adapter (~$50), Apple TB2 to FireWire 800 adapter (~$30), AND FireWire 800 to 400 adapter or cable (~$10). Is this correct? (I can't seem to find a TB3 audio interface for ~$100 that would be a better overall value than these cables.) Has anyone done this? If so, how bad is the audio latency? Thanks.