I tried only one.
The process I used was as follow:
Export the raw file in Lightroom with a max size of 500kb. The result was a 392kb jpeg.
Copy the file to our WD MyCloud.
Copy the file to Snapseed on our ipad.
Save the file in the camera roll.
Select "Choose File" and select the photo.
Select "Attach This File". It is at this point that I get the message that the file is too large.
Thanks,
Tom