By setting APPX_41_EPS=1 environment variable, you can get previous EP behavior.
This variable, however, can not be set for design. It is for Run time only.

Execution cycle in 4.2 has been changed in 3 areas:
1.      Input execution after OC
2.      Input execution on Delete
3.      Input execution auto execution of child process.


On #1 – input Execution after OC – if you have ORDER1 Input Process, and execute opt1 to run Line Items process, we changed execution cycle when you come back from a child.
The order of the events as follows:
1.      Read the PCF record with HOLD
2.      Executes Post PCF Read
3.      Executes Post Invocation of the Child
4.      Executes Select Image
5.      Executes Pre-Display/Verify EP
6.      Executes Pre-Display
7.      We display the Screen

4 – 6 – is what changed in 4.2.

On #2 – Input Execution on Delete – if you delete a record, Appx will execute Pre-Update EP, after Delete – Post_PCF Update EP.
Prior to 4.2 – Pre-PCF Update Ep wasn’t executing.

On#3  Input Execution auto execution of child process – Key change, record delete (for example, you have ORDER1 and ORDER2 as an AC to ORDER1. If you delete ORDER1 record, you need to delete all corresponding ORDER2 records).
It looks to see if ORDER2 needs to be run.
It executes ORDER2 in autoexecute, it goes through all the steps to delete ORDER2 records.

It executes:
Post PCF read
Pre PCF Update
Post PCF Read
Delete – Post PCF Update

It will execute all these EP’s for each line item.

In 4.1, it wasn’t executing Post PCF Read and Pre PCF Update.