Oh Carrie! Ivy has one of those. It's like a headband fashioned into a figure 8! It works really well for Ivy. She does EXACTLY what you are describing for Kyla. She can get up on all fours but then her raggety ann legs kick in and she flops to the ground with frog legs.
I'm sure that's why she prefers to inch worm.
Kyla will not like it at first (you're right) but she will get used to it. Good Luck! I am feeling for you and Kyla