.NET 8 migration

Hi,

Currently I have completed the migration from .NET 4.8 to .NET 8 and I am able to load and use the migrated project in Revit 2025 but not in older versions.

Do I have to use separate project/solution for the purpose of using my code in Revit 2025?

Or in other words, is there a way to use the existing solution without duplicating my code for both cases:

Revit <= 2024

Revit >= 2025

Thank you.