Hey there,
I see you're looking for somebody who has knowledge of bigbluebutton frontend html5 client customization I understand exactly what you're looking for, I have an expertise in BigBlueButton development, configuration, customization, Client Layout design and development, HTML 5 Client Customization, Load balancing of multiple BigBlueButton servers.
I have worked on BBB and its whitelabeling. i can change the complete layout of the BigBlueButton client with modification of core functionality. If you want a demo of my work then please ping me i will share my server link where you can check my customised BBB application.
You did a good job of explaining the role, but just curious - What kind of modifications you want in detail ?
Thanks,
Akshay