Almost every "homemade" bubble recipe on the internet swears by glycerin. But when the community (Soap Bubble Wiki) ran blind tests comparing mixes with and without it, the difference turned out to be minimal. Glycerin is a humectant: it holds onto some water and can slow evaporation a bit in very dry air, but it's not what makes bubbles big or tough.
What actually matters
What really moves the needle is the polymer, the correct dilution, and the ambient humidity. That's why KUANTIKA's engine doesn't reward glycerin as a key ingredient — it treats it for what it is, a mixing aid.
Does that mean you should ditch it? Not necessarily: in small doses it doesn't hurt, and it can help a touch in dry weather. It's just not the secret you were sold.