Configuration of Thunderbolt 3 ports for 2018 Mac Mini

You have four Thunderbolt 3 ports available on the Mini.

If it were me, I would just connect each device to its own

port and avoid any daisy chaining. You'll need another adapter

but it leaves any available daisy chaining ports available on the

devices if needed in the future and you would still have a native port

for your GPU.

Thought is why daisy chain if you don't have to since the daisy chained

devices share that chains bandwidth.

Put the OWC Envoy NVMe SSD and eGPU on different buses. (The left two ports are on one bus, the right two ports are on another bus).

Each bus controller has a 32Gbps combined data limit (PCIe3.0x4) and gives a 10Gbps minimum reserve to each port for guaranteed full speed USB 3.1 gen 2. However two TB-3 devices operating at full speed on the same bus can throttle each other from 22Gbps down to 16Gbps (2,000 MB/s) Thunderbolt-2 data speeds.

That's still fast enough that you might not notice the difference, but if you are paying for top performance you might as well balance the load.

The other limit to consider is the 40Gbps max data+video on any one port, but that probably doesn't apply unless you want to run dual 4K displays and high speed data through a hub off the same port.

The 2018 Mac mini comes with two Intel JHL7540 Thunderbolt 3 controllers, each chip services two USB-C ports.

Even though there is one chip, they still provide full bandwidth

for each port, unlike the USB "hub" chips used to create USB

ports on Macs and PCs.