Thank you both for your replies, I really really appreciate it!
Once again Farshooter you’ve saved the day! 
I sort of had the general idea, but couldn’t figure out what to use to ‘check.’ now I know the ‘IsValid’ node fits well for operations like these. I threw in an ‘Event Begin Play’ node to check for any isolated parts to begin with too, and added a branch to check if the actor in question is overlapping the landscape, in which case physics are not enabled, and the piece stays ‘buried’ 
Thanks again guys, I really appreciate the help & explanations!