Matthew,
I started researching the Irish Raid course about a month ago. I have started a conversation with Nic Compton (who wrote about it) and he said he would see what he could do to dig out details.
I would love to do it. We have a need to exit the UK for some of the summer (tax reasons) and Ireland would work nicely if we don't have to quarantine!
Other plans to Brittany and NW Spain look doubtful as of now...
Let me know if you make progress, and I will do likewise.