There is a great tool to send geometry from Maya to Substance Painter, written by Victor Kam https://www.artstation.com/morepolys.
You can download it from the Allegorithmic forum:
https://forum.allegorithmic.com/…
(the maya2painter.7z file)

Also I have a duplicated, modified version of it for UDIM. This is how you can do it:

• Duplicate the original plug-in folder
• Rename it (for example: maya2painterUDIM)
• open the import.qml file with a text editor
  Add this code to the end of the two alg.project.create line:
  ,[],[],{splitMaterialsByUDIM:true}
  for example in my case (I changed the path):
  original line: alg.project.create(“file:///d:/temp/exported.fbx”)
  new line: alg.project.create("file:///d:/temp/exported.fbx",[],[],{splitMaterialsByUDIM:true})
• Save the file
• Create two new icon for the UDIM version.

Cheers, D