I think you'll do fine, if the people are not looking for new ideas, then they will not even show up.

When people come to a table to discuss things, they are expecting new ideas, so people like this generally appreciate positive criticism, especially if it comes in a way that is easily received. Some people are better at this than others, and some people never have anything positive to add.

Sometimes, even when there is something useful in what they are saying, since they never learned how see more to communicate, it is hard to see if they have anything good to offer or not.