Future-path worksheet
Expand this display, or replace the weak link?
Another box of lights is not an expansion plan when replacements vanished, generations do not mix, the controller is full, or a quarter of the old segments are already failing.
Count the working system
Test and label every current segment before buying more. Compatibility research is much easier when you know the exact generation, controller, failures, and capacity you already own.
Current primary guidance: CPSC seasonal-lighting safety characteristics and UL indoor/outdoor marking guidance.