Definitely best to get that done ASAP. Forgejo being a drop-in replacement for Gitea won’t be guaranteed ever since the hard fork:

To continue living by that statement, a decision was made in early 2024 to become a hard fork. By doing so, Forgejo is no longer bound to Gitea, and can forge its own path going forward, allowing maintainers and contributors to reduce tech debt at a much higher pace, and implement changes - whether they’re new features or bug fixes - that would otherwise have a high risk of conflicting with changes made in Gitea.