Probably the issues that you will encounter would be related to Unity related API changes. However most of them should be automatically upgradable by Unity, while other may not. Other than Unity related API changes there are no other tests really necessary to be made. If you resolve the potential API changes then things should work out correcty. However I would still highly recomend to update to NodeCanvas 3.x eventually since there are really a lot of great features (and some bug fixes along the way) that are definetely worth it 🙂
Gavalakis
