Compositor Switch Node: Skip Evaluation of Inactive Branches
Currently, both branches of the Switch node are evaluated, even when only one is active. This causes slower performance in the 3D viewport. When unused nodes are muted manually, performance improves significantly.
Current behavior: both branches are evaluated → slower performance
Desired behavior: only the active branch should be evaluated.
2 Comments
Might be a bug, try reporting it, in Blender click Help, then report a bug in the menu. I've also had this issue.
They'll tell you if it's expected functionality.