Hi - Does anyone know if the Appian Salesforce connectors can be exec

All Writer functions (in your particular case: a!sfcInsert() and a!sfcUpdate()) will only work in SAIL form, and specifically only work with bind() function which require execution from user action within saveInfo parameter.

For you use case, you'll have to find or build a custom Smart Service plug-in, to be able to execute the update within process flow.

Or you use the available REST API. See forum.appian.com/.../Service-Backed_Record_Tutorial.html for an idea of how that could work.

@Angadc, no.

@stefanh are you suggesting to use Salesforce REST API?

Yes, the SF REST API could be a way to go.

The effort to get the REST APIs working would be significant. Our business case requires inserting, updating, and deleting data in Salesforce.
At this point, while not ideal, it may be easier for us to redesign our process and write the data before the user activity and user the connectors within a SAIL inteface in the user activity, so that we can leverage the connectors. I'm hoping that in a future Appian release these connectors would work in an expression rule. It would make them much more usable.