The ex, the colleague who'd take it wrong, families that don't say it, the person who's died, and when it's more than shyness
The rule in chapter 22 is for ordinary cases. Some aren't, and this chapter takes them one at a time.
The ex. There's a good thought about someone you're no longer with, and you'd like to say it, and you're not sure whether it's a kindness or a door left open. My answer is that it depends what's after it, and the honest test is chapter 8's. If it's a report with nothing attached, and you can both take it as one, it's fine, and it may be one of the more generous things you do this year. If any part of you is hoping it starts something, it's a bid, and you know it, and this book isn't cover for it. And if the split was recent or the other person is still hurt, the kindest version of the good thought is the thought version. Keep it.
The colleague who'd take it wrong. Some workplaces have someone for whom any warmth is an opening, and a compliment from you would become a story about you by Friday. Chapter 17's rule works here. Keep it about the work and not the person, keep it short, keep it in the moment, and don't repeat it. "That was a clear set of slides" is unspinnable. If even that feels unsafe with this person, leave them out. One a day doesn't have to include everyone, and the drawer is the right place for a good thought that would be used against you.
Families that don't say it. In some families, and some cultures, nobody says the good thing out loud and never has, and doing it would be a departure from more than your own habit. I won't pretend that's the same as a reserved temperament. It's a shared rule, and breaking it is visible. I'd only say two things. The evidence in this book comes from people who were also sure it'd be awkward, and the gap between their guess and the landing was consistent. And the small version, said in passing, about a specific thing, is the one that survives a family rule best, because it can be received as a remark rather than a declaration. Start there, and go slowly, and let the other person set the pace of what comes back.
The person who's died. There's a backlog for someone who isn't here to hear it, and the funeral speech was the first time any of it was said, and you've been carrying that. I've no research for this and won't invent any. What I'd say is that the backlog isn't wasted. It's the clearest possible evidence of what the drawer does, and the plainest reason to open it for the people still here. If it helps, write the things down, in the two-part shape, detail and what it did for you. Not for anyone. For the record that you noticed. Then say one of the living ones today.
When it's more than shyness. If what's stopping you isn't a guess about one compliment but a fear of most social situations, if you worry before, during and after them, avoid them where you can, and fear being watched and judged much of the time, the NHS says that's social anxiety and it's more than shyness. It's common, it often doesn't go on its own, and treatments help. See a GP, or refer yourself to an NHS talking therapies service, which you can do without a GP. Go anyway, an earlier book, is about the nearest habit and reads well alongside that. This book's rule is still usable, but it isn't a treatment, and I'd rather you had the treatment.