When designing our (no longer) offseason chain in tube drivetrain, I made the mistake of requiring an odd number of chain links. The design required fixed center to center distance (i. e. no tensioner), so we needed to use half links to get the appropriate length of chain. We first tried vex half links, but these had long pins that jammed in our 17t Andymark double sprockets. Mcmaster half links worked much better as they are the same width as regular 25 chain links (no cotter pin).
More importantly, make sure that you use center to center distances with even numbers of links, because half links reduce load capacity by up to 30%. It’s worth noting that master links also reduce load capacity by up to 30%, so replacing a master link with a half link isn’t a big deal (Source: https://www.diamondchain.com/wp-content/uploads/2017/03/TechnicalEngineering.pdf).