Sounds quite cool... I don't have any "reasonable" use for it, but did land a rather nice smart switch

so it's more like wanting to try things out experiment and learn about networking. I'll run the mini in a LAG and see what happens
And thanks, for the detail! I appreciate it
I am guessing you know how to set up the aggregate link but just in case:
1. Make sure you have two or more ethernet connections connected to the Mac. For example 1 on-board gigabit ethernet link and 1 T-Bolt or USB3.0 gigabit ethernet adapter.
2. Make sure they are both connected to the switch and are pulling an IP address each (i.e. set up as two standard gigabit connections to the Mac)
2. Go to Network Settings.
2. Click the drop-down settings box ('gear' icon next to the +- buttons) at the bottom of the network connection options window.
3. Choose Manage Virtual Interfaces.
4. Click + and New Link Aggregate.
5. Highlight 2 or more links (I am assuming you will have only two though).
6. Name the aggregate link. I used 'Dual Gigabit'.
7. Click Create.
The switch must support the IEEE 802.3ad (which I believe is now called IEEE 802.1ax). Generally the specs will say link aggregation is supported. If it is supported then the lights will go green at step 7 above, but if link aggregation is not supported then the lights will remain red. I say that because I found one switch that did support aggregation even though is was not set out in the specs.
From memory you may need to reboot or wait a minute for the link (green lights) to become active (at point 7 when you click create).
Also I remember that the IP address that is the lower of the two is the one used for the link. I say this in case you need to assign an IP from your router. In other words if one link is 10.0.1.10 and one is 10.0.1.11 then the IP for the aggregate link will be 10.0.1.10. This is really only relevant if you use static IP addresses and you forward ports etc.