I did Pawtucket -> Kendall for about 2 years, on a once or twice a week cadence. I took the train from Attleboro which limited me to the commuter rail.

On mobile but maybe later I will repost advice I gave the last time a similar question was asked. Here are some general thoughts on the negative side.

The problem with the train commute is you have to be there when the train leaves. If you miss the train it adds a lot of time. This used to be easier to deal with in PVD with Amtrak but they have reduced service. Anyway, because of this large change in time (30-60 minutes depending on when you are going) with a missed train, you have to make damn sure you are at the station when it leaves. This means if you have a 10 minute drive to the station +/- 5 minutes, you have a 15 minute drive to the station. You will quickly learn not to take chances.

I regularly had 8 AM meetings. This fucking sucked. I'm just going to be straight up with you. My timing was such that taking the 6:34 train from Attleboro would get me to the office at 8 AM if everything went right. I couldn't rely on that so guess what - 5:34 train it is. My boss gave me a 15 minute late pass on days I commuted which was enough cushion but some meetings I had to be there on time.

Same thing coming home. You have to be absolutely militant about leaving the office on time. No last second conversations to talk about that one email. The red line has some variance, though you are going against the commute (I think you are going to Andrew based on your post) so it should be a bit more consistent. Still, it is often a bit late. So same deal. 6 minute headways again now so I would give 15 minutes from arrival at Andrew to arrival at the CR platform as a worst case and again, you have to plan around the worst case.

the upsides are that it is hella better than driving, the train can be relaxing sometimes (though the rush hour trains are stuffed between Canton or Sharon and S.S.). It is more reliable than people credit. I like the way they pour a Guinness in the pub in South Station which made missing the train more tolerable. To be honest, the worst thing was timing the transfers and how packed and miserable the red line was. If I could have walked from South Station to the office it would have been much better. And, it might be better now, I was commuting during the MBTA self-destruct sequence of 2021 and early 2022.