Sorry for the delay, I've had some personal issues to tend to.  And when I do get back to this forum, I sometimes find it difficult to find what I need to respond to.
I've made progress using the REST API directly.  My first app looks at recent orders and then applies a set of rules to add tags to the customer.  
While this works, it is not pretty.  I would much rather use ServiceConnect.
I've tried Googling for how to create a custom ServiceConnection.  The only thing I've found was a 2017 Stack Exchange post.
But, it seems like a great deal of additional work for what I'm trying to do.
Does anyone know of other examples creating custom ServiceConnections?
Thanks.