The most absorbent store brand product in the U.S. by FAR also happens to swell like crazy. Check out Kroger, Rite Aide, or CVS Overnight Underwear (They're all the same product). These are pretty damn good performing adult pull-ups that have standing leak guards. They are fairly thin when dry, but give them a good wetting and they swell like crazy. I usually use these when I'm on the go and need something I can change quickly and easily but don't really need long term absorbency (for me they're good for one full void and them some extra).
Due to how thin they are when dry, I can wear two or three of them without any real bulk. This allows me to still wear protection, but be able to change quickly as I can just tear off the used one and have a clean one ready to go. This combo is especially helpful when I have a lot of short classes on a given day. On the flip side, if I only have a class or two but they are longer and have a lab as well I'll usually be in a NorthShore Supreme.
Give the Overnight Underwear a look. I think you'll be surprised at how well they perform.