About the workflow to send video at scale:

Why aren't you using phantombuster email discovery service instead of SalesQL? That could simplify the process.

Also it could be interesting to check "Save the profile's picture as a jpeg" to have it as personalisation option for lemlist.

Last but not least, why aren't you using the phantom dedicated to lemlist integration?

https://phantombuster.com/automations/toolbox/4201331544314519/linkedin-search-to-lemlist-campaign