I've just stood up a new PAM environment with version 4.3.05 and started testing some of my processes that I had migrated over from our current 4.3.02 environment. In 4.3.05 I've seen that it takes between 20-40 seconds to kick off a process using the Open REST API. On 4.3.02 it would typically take about 2-5 seconds to launch a process like this. From the UI I'm not seeing any delays in starting a process, only a delay between the time the API call is made and the time the process shows up in the UI and starts.
Release : 4.3
Component : Process Automation
CP01 and CP02 were applied