I’ve deeply pondered pain stockinette amongst stranded colourwork patterns. I feel that if the majority of the project is stranded with floats, it would be reasonable to do the same with the single colour if you have two balls of it, just using a basic combo like “[k3 mc, k3 cc] rep to end “. You wouldn’t see it but the tension and thickness of the garment would remain the same as the rest of the garment.