Question about Razer Core X

I have mine working with a Nvidia 2080Ti with three monitors connected (one of them 144Hz), and with Windos10 runs good (4K is not a problem).
I was still not able to test on a MAC as none of mine has a Thunderbolt 3 (USB-C) connector, but your Mac Mini 2018 should have it.
In my case, it was mandatory to have the latest Nvidia Geforce Drivers installed, in your case it will be AMD Catalyst for Mac OSX. You should check if they are available for you (although in theory it should be possible to make it work with a little bit of extra effort)
Anyways, if you want to go for a better Mac & AMD compatibility I'll suggest the 'Sonnet eGFX Breakaway Box 350 (Extern)' (available right now at digitec), or if your budget if not too restricted and want to opt for 100% Mac compatibility, you'll have another options like 'eGPU Pro Blackmagic', that also comes with a Radeon Vega. Hope the information helped you.

Halo, I also have a question regarding Razer Core x. I have the new Mac Mini and wanted to connect the new Radeon 7 with the Razer Core. Unfortunately Windows under Bootcamp does not accept the card, or the drivers. In the device manager it is listed with the warning triangle.
Probably I have to wait for an update from Apple to support it? After all, it's the same chip as the Vega64, which apparently works with the Razer Core....
can someone maybe help me with this? Would be very glad.
Best regards