We use the built in task approval process for gate reviews. It works well for us. We have it tied to the In Progress status. After approving a gate, the approver is supposed to manually change the status to Complete (we don't have Fusion).
We used to have approvals triggered to a status of Complete, but we ended up not liking this. When viewing the task list, you then couldn't tell what was Complete and waiting for approval vs. what was Complete and approved.
This flow works for us.