Capture One users on macOS now have the first ever tool to send files directly from Capture One into new Affinity Photo as Focus Merge, HDR Merge, Panorama, and Stack documents. Watch the video to see how it works.
This tool does not provide a full round-trip. It makes it fast to create the new Affinity Photo document and load the files into the file list. Most of these merge documents have settings you can tailor. For that reason the tool stops there and lets you take over. You will select your settings, do your merge, export your output, and import that output back into Capture One.
You can get this tool from my Extras page for a $20 donation.