Triggers not working in conjunction with "Out of office" app

I could not believe it, but it seems it's true, according to the reply I received form the Zendesk customer support team.

Because we started working on portfolios of at least 1000 thousands customers and counting (meaning customers entering a certain portfolio, migrating to a new one or churning), we needed to set up 10 triggers which would route tickets to agents after manual tagging. This was the easy step.

Next up, we wanted the same trigger to route the tickets differently when the agents who would normally receive the ticket is on vacation (set as "unavailable" in the out of office app). 

We tested the following condition: [Out of office] Agent out? -> is -> Checked/Uncheked, and neither does the trick completely. In the first hypothesis, it does not route tickets once the agent returns to "available", the second one does route tickets to agent even though "unavailable" is on.

It seems there's no solution or workaround, as the reply from the customer support team is "Upon further research, I see that this is a current limitation on the app. The app will only restrict ticket assignments if tickets are being updated manually thus assignments using Triggers, the Mail API, Rest API, and bulk updating tickets can bypass the restriction. For more information, please see Known limitations."

I was recommended the "Round Robin" app, but with the following reserve: "Please note that the Round Robin App is a third-party app thus any issues encountered during configuration or setup should be reported to the App Developer for further assistance." 

Manual assignment in the second decade of the 21th century.

Thank you,

George