RootsChat.Com

You can find indexes to the bmds for the counties now known as the Republic of Ireland up to 1958 on Ancestry, FindMyPast and Familysearch.

After that, you can pay for searches and copy records in the GRO by email.
https://www.gov.ie/en/department-of-social-protection/campaigns/general-register-office/

Newspapers are a good way to look for more recent deaths: irishnewsarchive.com

I queried St Ita's about burial records last year (someone who was an inmate).
They don't have any details of who was buried there but did acknowledge there is a cemetery.

I have two sources. One is the Ireland, Abstracts of Wills and Marriages, 1620-1923, and the other is Ireland, Select Marriages, 1619-1898.
I had a look at the RCB list but I don't think the registers for the parish church of St Catherine's have been extracted anywhere.
The only other route is to try the newspapers, but I haven't found anything on Ancestry.

The first of those collections includes the second, so they are the same source.

It works - I've tested it out.

I think this should probably be a different thread than the census website discussion, but here's my review of the new Irishgenealogy site.
https://cbgenealogy.ie/new-site-for-irishgenealogy-ie/