Creaking chain under high torque
I run 46x16t on my SS daily commuter. Current bottom bracket is the Shimano BB UN300 square taper. I threw a new KMC SS chain on about 100 miles ago. I clean and re-lube the chain and bike after ever wet ride. I've noticed that when I'm putting lots of torque on the pedals (SPD clipless if it matters), either from a standstill at a stoplight or when climbing up hills, the chain seems to creak. The tension is as it should be and accommodates the tight spots of the chainring which has ~2000miles on it.
I removed, re-greased, and reinstalled the bottom bracket which is relatively new (<500 miles) and did a deep clean of the chainring and cog. Upon measuring, the chain hasn't stretched yet, but I'm at a loss of what else I should look at. Any thoughts please?