Any plant you choose to bring into a cat’s home should be both safe and allowed for her to taste.
Here’s a list link: yes it’s evil Amazon but you don’t have to buy it and the picture is useful. https://www.amazon.com/Magnetic-List-Toxic-Plants-Flowers/dp/B08PZG8SY2
Edit: my cat also loves grass, both the oat/wheat/barley “cat grass” you can grow, and also the “serious gourmet shit” (I think it’s probably crabgrass) that comes up like a weed in my balcony plant pots and I bring in for her. It doesn’t make her barf, it’s fiber for poop.
You could possibly mitigate the problem by keeping the battery out of the scale except for the few times you use it. Or add a snippet of tape you peel off and replace. Will the battery for the calipers fit in the case separately? It would be a PITA but so is constantly replacing them.