This recent idea reminded me of something I have wanted for quite some time now: the ability to determine if a property is read or write based on wiring, not some half-buried option in the right-click menu.
The basic idea is simple: all properties have two terminals, one for writing and one for reading (except read-only of course). No right-clicking, just wire up the direction you want.
The bottom case is a bit interesting. I see a few possibilities:
1. Passthrough (cosmetically saves branching, crossing, etc.) Same behaviour regardless of errors.
2. Read then write : returns previous value. What happens if there is an error? Passthrough, old value?
3. Write then read: almost always passthrough. In case of error would it return old (ie. actual value) or passthrough?
4. Do not allow this.
I would expectit to perform the write and then the read (3) or passthrough (1). What is more important to me is the actual value and not the intended value. Mentally I just see data flowing into then out of the PN when both are wired.
Bottom line: I see no reason not to permit the wiring to determine read or write of a property.
If there is a cop-out lack of consensus and simultaneous connections are not allowed, I would at least ask for a keyboard modifier (say shift) such that I can shift-drag to expand the PN and get the same property repeated instead of going down the list. Then I could at least do the write+read with a lot less mouse movement.