An Irish work holiday visa can only be requested from outside the country and has a maximum validity.

https://enterprise.gov.ie/en/what-we-do/workplace-and-skills...

That's not a renewal. It's fairly standard for EU countries to require being outside the country to apply for a visa or residence permit when it is your first one, or (in some cases) when changing the type of visa or permit. But renewals never need you to leave.

Ireland is not part of Schengen.