OC2 - Conference speaking evidence - different place same topic

Hi everyone,
I would like to ask about OC2 evidence. Is it possible to use evidence from two different conference speaking engagements that are made at different times and places, but they cover the same topic?
Or should I change the topic as well?
Thanks,

Martin

Two diff conferences with same topic is fine until each was a leading event with 100+ attendees and you have snapshots of you on main stage.

Thanks for the advice.