ProductCode as Realease parameter - works but supported?

[Andreus]

  I've got InstallScript project developed with IS2012 couple of years ago by other developer.
It's multy-instance project designed to install family of our products with one IS project.
Each project release is conceptually different product with unique GUID value stored in release overriden path variable ProductGUID . 

  ProductCode  (renamed ProductGUID  of IS2012) project property can't  be associated with path variable by IS IDE - Project Settings has interface to assign static GUID string only but not path variable like Product Version  or  Product Name.

  I've upgraded project to IS2019 and lost multiproduct functionality due to project property 'Product GUID ' rename . Fixing it I've found project xml file was edited directly  - Property table contains (now upgraded to IS2019 scheme)

<row><td>ProductCode</td>

<td>&lt;ProductGuid&gt;</td><td/>

</row>

* <ProductGuid> is Release overriden path variable

and IT WORKS as expected with IS2012 and IS2019.  It looks like half-documented feature or feature in "gray zone", but very convinient. IS help has note 

changing a project’s product code is typically not necessary and should be approached with caution.

but that's not our case. We "switch"  GUIDs  "with caution".

Is it UNSUPPORTED FEATURE?  Should I split project into 5 separate ones to keep it supported in next IS releases? What about make it supported and documented?

Very much like comments of  IS support and developers(silver maintenance). Thank you.