How to run same workflow code on different gallery with different host in Email Tool

[Yongcan]

Hi All

Current Case:

DEV Gallery, Email Host: DEVHost

UAT Gallery, Email Host: UATHost

Current Approach:

We do not allow user directly save workflow via Designer and must extract from DEV then publish to UAT via admin API and before migrate code to UAT gallery via API, due to Email tool ,perform "Find and Replace" with Email Host.

Now we would like to avoid performing such  "Find and Replace" 

How can I run run same workflow code on different gallery with different host in Email Tool?

One option out there is new DCM feature but maybe not an option for us ( setting up sandbox to check out).

https://community.alteryx.com/t5/Analytics/Introducing-Alteryx-DCM-Environment-Connection-Handling/b...

Was thinking create a wrap Macro and pass host info to eMail tool, however I'm struggling to create same interfaces of email tool of macro.

Currently I'm exploring Alteryx SDK.,Is it feasible to create a custom Email tool SDK version with similar UI ( without Server host info) and populate host within it? ( below picture describe the expectation of SDK approach) 

[Yongcan]

Just a update. 

We managed to create the custom macro with UI SDK as needed.