I've got friends back there who are Catholics as well. I nearly married one. The older demographic I know tend to have rather similar concerns finally. I do also look at polling on changing attitudes sometimes.
I'd agree with you that SF has lost votes up North by being pro-life. I think you got what I was saying on abortion arse about face there.
About 60% of the N.I. population are not dogmatically pro-life. Very few people actually take the extreme position of the big N.I. parties on this <20%. Unsurprisingly such views tend to correlate with the Church going part of the population just as it does in the RoI where the Church lobbies hard against abortion. That's not to imply it's a clerical conspiracy. A lot of religious folk are genuinely troubled by abortion and they are a big constituency that votes reliably. The Church can't really be avoided in Irish politics. The DUP sprang out of one. Its stance on abortion isn't a vote winner but it's not just cynical political calculation either. I did hear the DUP had been trying (and failing) to win over conservative RC's on the basis of it. Talk about leaps of faith! But then that did finally work in US politics which influences them heavily.
There is a lot that these two big rather nutty Stormont parties passionately advocate for that really does not appeal to their broader base. People are losing patience with that but they are locked into voting for them for other reasons.