This option will work fine, for the most part. However, I did notice one tiny hiccup for me. I had attachment fields on the form where I wanted to add my save and close. When adding an attachment, the iframe would refresh and cause a 2nd html save and close button to appear on the layout.
Also, using Jeff's input, I was able to use an HTML 5 object called sessionStorage to add a "flag" or an attribute to the record that helps you to close the record after the save.
I believe Nolan's method was using cookies. Which works just fine, but I just wanted an alternative and using Jeff's input, I used the sessionStorage object.
Find the code attached below.
*insert all disclaimers here... I take no responsibility for use of this code. This is just loaded here to acknowledge the wonderful sharing members of the community and post my final output of all their help.
Thanks again guys!
Next task is to override the master email button when using advanced workflow...
UPDATE: 2018-04-11 - Discovered that the previously attached code will be quirky in version 6.3 P5.
Reason being is that they brought back save and close button with this version. However save and close doesn't seem to be available for apps with AWF.
So, for those of us using apps with AWF still wanting the save and close, you need to make a minor update to this code.
I haven't fully tested, but the attached code references the master_btnSave. With version 6.3 P5, the master_btnSave is the Archer save and close.
The Save button is now actually master_btnApply.
If you understand custom objects and open the save and close attached files, this will make sense.