https://www.sidefx.com/docs/houdini19.5/news/19_5/index.html
Seems like the default builds are 3.9, but there’s the option for 3.7 too (Py2 has been dropped)
I’ve found modifying the .param file to add a 19.5 entry and also copying the python3.7libs folder and(or) renaming it to python3.9libs allows me to send a simple houdini scene with Mantra or Karma render node over Deadline.
Modifying the Mantra .param file also allows 19.5 mantra ifd rendering over Deadline (still missing 19.0 here!)
Seeing quite a few different places using PDG/husk to render but having to grab the plugin from SideFX
https://www.sidefx.com/docs/houdini/nodes/top/deadlinescheduler.html#pdgdeadline-plugin
There’s a few people writing submission tools too