Is it possible to achieve low latency streaming between two DAWs / audio applications?
You should definitely be able to achieve very low latencies between to instances of Connector in different audio apps, even over the network. It just needs a bit of tweaking regarding the receiving buffer and maybe both apps buffer sizes.
The first thing to consider before setting up buffer sizes in Connector is the buffer size used by both apps. It will work best if both are using the same buffer size, or at least if they are multiple of each other (for eg. 128 & 256 samples).
If you are using both apps on the same machine, you should not have to change the Sender Connectors Packet size. "Auto" should be fine: it will use the application's buffer length.
You should however change the Receivers buffer length so that each receiver has at least twice the length of both apps buffer length (sometimes 3 times will be more stable). If apps have 128 & 256 for example, a buffer of 512 samples or more should work fine ("auto" might be a bit misleading, but it is explained in the manual that it actually means "no extra buffering"). Just increase the receiver buffer size to avoid drop outs.