Waiting to the end to ask your question is a skill. Actually, it’s several skills. One is patience, the aptitude for waiting a little while for the itch to be scratched. Another is listening; if you can keep hearing and integrating meaningful inputs while a question is burning at the forefront of your brain, you’re doing something meaningful and hard. Deliberation is another skill you’re showing when you hold your question, because you’re allowing the question to improve with more information, to become more focused and targeted.
Jumping in with an urgent question before a person has finished speaking feels active and urgent, but it’s really lazy.
YoRocko! 
Thank you for wise advice. I often find myself with a question a the beginning of a Q&A session, carefully waiting until after the speaker finishes, only to find out no one else wants to dare go first. I sometimes ask a strange question just to get the discussion going, but these thoughts will help me stay organized about how to start.