Yes, I do. Right now, I have a container of iso-pro low carb strawberry on the go. I've been using water, frozen spinach and frozen fruit. It's nice and keeps me full for a long time in the morning. For about 200 cals and 36 gms of protein.
My next container is Nutrilite Whey Protein Powder, Vanilla Ice Cream Flavour. Two scoops of that will give me 220 cals with 50 gms of protein. I chose vanilla so that I could continue to add fruit.
I've used these kinds of drinks for years. I cannot get myself to eat breakfast so they work well for me.
ETA ... that's not what you asked was it
But yes I have used them for inbetweenies too. It's an easy fix.