Have you tried it yet? I thought all the hardware and software was pretty much there-they just hadn't gotten the cert to officially say it yet due to some weird edge cases, and in the meantime people have been successfully using TB eGPUs
I love it.
It mostly worked with minimal fuss. From what I remember, most of the headaches were getting sway and my multi monitor support configured to my liking.
edit: fix gpu name
The most popular choices seem to be Razer Core X or DIYing it with an ADT-Link R43SG (https://community.frame.work/t/my-portable-egpu-setup-adt-li...)
I'll skip a few intel generations and upgrade later then :), the only downside for framework is still the battery life, even with all the tweaking.