Hi pozdnyakov, do you mean case like this, when render process receive message, it is executing blocking script at that time, and after a long time(> hardcode time), the script logic finishes? 
For this case, the render process will firstly finishes script execution, then send ShouldSuspendACK message to runtime process, then runtime process gets ShouldSupendACK message, then sends Suspend message to render process, so render process is able to do OnSuspend() callbacks. This will not cause app pending.