Cherry shrimp can thrive in smaller, un-filtered planted vases, including those under 1g.
You can even skip having a substrate if you go with plants mounted on driftwood--with the low bioload there's enough surface on the wood and plants for beneficial bacteria to grow, though I generally include at least a thin layer of substrate even if I'm not planning to have anything rooted.
Depending on the design of the vase, the distortion can actually work in your favor, magnifying the contents making the shrimp even easier to see, at least if you line 'em up at the right angle.
Plants can be problematic, but I've found that even plants like hygro 'sunset' will grow slowly and stay small longer in these small planted vases with minimal fertilization and low-medium light levels.
I've got cherries breeding successfully in no-tech (no filter, no heater) planted tanks/vases at 3g, 2.5g, 1g, and .75g as well as same-sex groups of cherries in .5 and .3g bowls. All have been up and running for 6-12 months.