Just looking at a potential relationship between the placard location and jump..
IMO it is probable the Placard exited the plane when Cooper descended the Airstairs right after talking to crew at about 8:05. So, with some math using the Placard location we might be able to determine a jump point and LZ.
If the Placard exited at 8:05 was found at X and Cooper exited at 8:10, where did he land?
Unless you can prove the time stamps are incorrect, you have zero to go on...they would of known if Cooper started down the stairs at 8:05, 06, 07 etc..no colored light will help this either..they felt the oscillation and reported it, and it wasn't at, or around 8:05..the transcripts would read "8:07, we are getting oscillations in the cabin, he must be doing something with the stairs" end message...nothing implies a time several minutes after his last contact.
The main concern seems to be the difference between the oscillation vs a pressure bump..the other problem seems to be the failure to pinpoint the location..
You always have to go with the known evidence, unless you can prove the evidence inaccurate, or wrong...time stamps are hard to beat..how do you know it left the plane at 8:05?
Is the current going to be the same on the bottom?
First, reasoned assumptions..
Cooper did not descend the Airstairs prior to last conversation with crew as comms are at top. He wouldn't go down and back up.
The placard did not exit the plane until the Airstairs were opened beyond 20 degrees. There is no wind at 20 degrees and the opening is small at the end. That had to be after the last conversation with the crew.
Now, the key is not the timestamp as it is not precise to events, but the time spread between events is more accurate. The timestamp itself is irrelevant, I used the time spread between two events and added it to the location of the plane when the placard left it based on drift and found location.
Take placard find GPS
Adjust for drift = plane location when it exited plane (it just happens to be close to the 8:05 mark on FBI flight path but slightly West)
Take speed of plane x 5 min = Oscillation > where Cooper left plane
Adjust for drift = Cooper LZ
I used 5 minutes time spread but even at 4-7 minutes, the LZ will be close.