On Thu, Jun 23, 2022 at 11:05 AM, Robert Benward wrote:

• When I add a second MCP23017, does the addressing continue to GPIO (16...31)? How do I guarantee the correct order between the two devices?

You don't, one GPIO device is supported.

• When there is a conflict in "#define" between the config.h and the pinmap file, which takes precedence?

Depends... but common settings are #ifndef bracketed so that Config.h takes precedence, for others it could go the other way