I didn't comment earlier because I "only" had a valve and one CABG done in 2013, but happy to say that, broadly, all went fine. I wasn't expecting the CABG but they decided to do it as there were signs that artery was going to need bypassing in the future, so decided "whilst we're in, let's do it". I am not knowledgeable enough to comment about whether risks of all-in-one surgery increases risks, but it does seem logical to me. The alternative is further surgery sessions, which come with their own repeated risks of course.
The caveat is that I had a complication that can happen to anyone having valve surgery on it's own even: I ended up needing a pacemaker as well. Apparently this affects less than 3% of people, and is why they put in a temporary external pacemaker anyway: just in case it does happen. Inserting the pacemaker was done a week later, and is very minor by comparison. Overall, post surgery I was in hospital 18 days. That was all 10 years ago now, and I am on my second pacemaker.
The caveat is that I had a complication that can happen to anyone having valve surgery on it's own even: I ended up needing a pacemaker as well. Apparently this affects less than 3% of people, and is why they put in a temporary external pacemaker anyway: just in case it does happen. Inserting the pacemaker was done a week later, and is very minor by comparison. Overall, post surgery I was in hospital 18 days. That was all 10 years ago now, and I am on my second pacemaker.