ID 546410 - Using beforeFrameRender callbacks to update node values doesn't update the render as expected

Problem summary
Using beforeFrameRender callbacks to update node values doesn't update the render as expected
 
In this example, a Switch node should change it's input to it's input +1, with the script starting at input 0. This means input 0 should never render:
 

 
Customer reported version
nuke.13.2v5
 
Customer reported platform
centos7
 
Steps to reproduce
 
1) Download the attached beforeframecallbackbug.nk nuke script

2) From a command line, render 5 frames of the Nuke script, for example:
 

C:\Program Files\Nuke14.0v5\Nuke14.0.exe -x -F 1-5 <path\to>\beforeframecallbackbug.nk

 
Notice that the beforeFrameRender prints the expected input for the Switch node for each frame:
 

 
3) Open Nuke
 
4) Read in the frames a view them, they have been rendered as if the callback happened after the frame render
 
Expected behaviour
For the beforeFrameRender callback to update the nodes before the render happen
 
Actual behaviour
The print statements happened before the render, with the correct values, but the image rendered does not match 
 
Workaround
Unknown.
 
Reproduced by support
This bug has been reproduced in:
Nuke 14.0v5 - Windows 10, CentOS 7, macOS Monterey
Nuke 10.0v1 - Windows 10
 
 
Earliest version tested
Nuke 10.0v1 - This issue appears in all tested versions of Nuke