As I have warned you on my previous post, there was an issue where the OnAfterValidate Event wasn’t fired as expected.
Yesterday Microsoft has released CU5 of NAV2016 with a platform hotfix special for this behavior as you can see.
So from now on we can use these triggers without special tricks.
You can download the new CU update from here (Partnersource/CustomerSource Login required).
And enjoy using Event Subscribers.