Per Marions request I am posting this response here as well in hopes in can be useful to someone else!
I’m a little late to this post, but wanted to let you know that Sunwarrior, is an excellent protein powder. It’s vegan, and comes in both vanilla and chocolate. I’ve done a lot of research on this as I was trying to find the most “pure” version of protein powder out there for myself, as well as for my dad. It tastes really great, and you can add a bit of it to almost anything.
Also, since a lot of the adult pre made shakes don’t taste great, on the advice of a nurse friend of mine I tried Pediasure, in vanilla, as a possible alternative. Same nutrients, but much better taste. I buy the mini bottles of them from Costco and my mom adds a mini bottle of that as well as the powder to a shake she makes for my dad each night with ice, almond milk, frozen yogurt, and occasionally pumpkin puree. Hope this helps, good luck!