Broken: 2.82, master, ece4515fc8aa, 2019-11-04
Plugging a Vector/Colour into a Scalar node group input produces a Scalar output in cycles, however in EEVEE it remains a vector.
I understand this is due to node group optimisations in Cycles, while in EEVEE node groups "disappear" during shader compilation.
I don't know which behaviour is preferred, but I assume there would be some small performance impact if every node group input/output was cast to it's respective type in the generated GLSL, so maybe a conditional check to see if the inputs match the expected type?
Steps to reproduce:
Left is LookDev/EEVEE, right is Cycles.