Houdini is an exceptional tool! It took me a few tries to get through this press release... this only seems to change things for companies using the engine plugins that make >$100k.
I ran into this recently when we needed an interactive rendering technique that Houdini doesn't support. The Houdini Engine API would have been perfect, but we use Indie and it doesn't support anything but the official plugins.
Instead, I'm writing HDK nodes in C++ that accomplish the same thing by copying to shared memory in a subprocess running Optix 7. It works, but it's ugly as hell. Oh well.