so I got back to dublin and just went in for a PCR test at the RDS. the website said they were taking walk-ins, but when I got there they were apparently no longer accepting walk-ins. the guy at the gate who was managing traffic let me know me the hack — go away, book an appointment on your phone (doesn’t matter what time), and come back. So I did that, was let in, and was able to get a test done straight away no problems. not sure if this might help anyone else but it was certainly handy for me.