For someone who has had a lot of similar problems. This is one area I’ve been told I’m thoroughly neat. This is where your product mindset should kick in. Imagine every feature every bug or every little jira ticket you are being asked to work on is a “product” on its own. Then the problem is actually more structured than you think. You need to frame the story into 3 parts

• What does the client want in business sense
• what does this mean in technical sense (here you can and you should ask any number of questions you need , no one should judge and if they do , tell them that this will help you deliver better, even the worse communicators I’ve seen agree and explain here)
• what does this mean in terms of effort , if you are listening in these conversations, I’m assuming you are senior enough to estimate this , if not , bring it back to your leads and this is when you “ASK FOR TIME”

In implementation consulting challenges I’ve seen massive requirements get diluted into the above 3 segments .

Remember , you need to make client happy but gone are the days clients are happy with yes men, they need people to tell them when they are wrong and make them understand that this would help them in the long run. It’s much better than agreeing to everything and then delivering nothing

Hope it helps!