Various versions of Platinum have bug fixes and also introduce new bugs.
So for task X, version A might be appropriate.
But for task Y, version B is better.
 
Because rolling back and forth is no fun I currently find myself doing final mixing in X3, which is ridiculous.
 
Please make it possible to have multiple versions of Platinum installed and accessible at the same time.
 

It is possible to do this now with the actual SONAR program folder. ATM, I have releases D through N installed. It involves using the same shared files but X3 uses them too so it appears this solution will work for you.
 
Here is what to do.

1. Roll back to a particular release
2. Copy the "SONAR Platinum" folder to a new name. In my case I started with Dorchester. After installing Dorchester, I copied the "SONAR Platinum" folder to "SONAR Platinum-D"
3. Roll forward to the other released and repeat step 2 copying each release into a unique name.

 
Going forward the process is the same, copying the new version into a version specific folder with each new release but leave the current version in the default location too.
 
To run a specific release go into the release folder and launch the SONARPLT.exe
 
 

scook
It involves using the same shared files but X3 uses them too so it appears this solution will work for you.

 
Amazing.  Thanks for providing a solution to something I was wishing for.
I guess it also means that the Windows Registry entries are also shared, but I don't see an obvious problem with that.

Yes, the registry is not a problem. Here is a little more detail.
 
To clarify, in this post when I refer to a SONAR version it means, for example, SONAR 8.5, X1, X2, X3 or Platinum. A SONAR release means, for example, SONAR Platinum Dorchester, Manchester or Newburyport.
 
There are a few registry entries used by all versions of SONAR (and other Cakewalk products). Most registry entries are stored by SONAR version. IOW, for X3 has its own registry entries and Platinum has a separate set of registry entries. All SONAR Platinum releases use the same registry entries.
 
There is one VST inventory for the X series and before. There is a separate VST Inventory for Platinum. All SONAR Platinum releases share the same VST Inventory.
 
There are other version specific folders such as the user directory, Cakewalk Content, ProgramData. Just like the registry, all SONAR Platinum releases share these folders.
 
Because there is only one set of registry entries for Platinum, each release must be in the same parent folder. For example I use the default location so the current production version is located in "C:\Program files\Cakewalk\SONAR Platinum" and the others are in "C:\Program Files\Cakewalk SONAR Platinum-D", C:\Program Files\Cakewalk SONAR Platinum-E"..."C:\Program Files\Cakewalk SONAR Platinum-N."
 
I do not have a 32bit version installed but the layout is similar except user directory, Cakewalk Content and ProgramData are shared between 32bit and 64bit versions.