I would love it if the Call By Reference node had a "don't wait until done" option, so that we can stop using the inconvenient and inelegant Set Ctl Val method or other inconvenient ways to pass arguments to dynamically called processes.
I believe the main issue with this is what to do with the outputs from the subVI (since you won't be able to use them) and I can think of two options:
1. This option would be settable at edit time and would break the caller if you wire any of the outputs.
2. This option would be settable at run-time and you would get default data from the outputs and an error or warning from the error out terminal of the node if you wire any of the outputs.