Finding CSEP Eligible Companies?

I am an American working in IT, currently trying to find a job in Ireland in order to immigrate. I have a spouse I am trying to bring along with me, so CSEP is a requirement for me. I already know what job titles I'm looking for, IT is all over the Critical Skill list, but there's two things throwing me off-

1. Are there more specifics on what makes a company CSEP Eligible? I know the employer needs to be "Based and trading" in Ireland, and it has to have at least 50% EEA nationals working there, but I'm wondering about nuances regarding, say, an Irish division of a multinational company. Is there a trick to know, or is it more forgiving than I fear?
2. When reaching out to recruiters and prospective employers, when should CSEP enter the conversation? As a non-negotiable, I don't want to get to the end of a process to learn it wouldn't work right at the end; But I also don't want to scare off an opportunity by mentioning too early. For context, as much as I think I have a lot of selling points, my actual work experience in the field is still less than a year; I assume I need to be more tactful than someone who can let their years of experience speak for itself.