Hey Argon, welcome to the forum, but I’m gutted to hear you’re stopping your Huel journey so soon. What have you tried so far. Use Huel as a base and experiment. There are so many things you can do to adapt the flavour and texture!
There is a video here (please excuse my sub-par performance)
Or you can scroll down on this article to ‘Powder Hacks’
Thanks to the squad here for helping with the seal and sharing other ideas - you da best 
Good question and one we considered a lot. @Smep is on the right track, there were loads of reasons and different perspectives on it though. I posted our reasoning here, 2nd half of post! If you are interested!
Yup, we didn’t like the designs with the cap attached while maintaining the asymmetrical design we loved so much. It generally involved using a tether and we didn’t like the drinking experience. Our old buchsteiner had similar tethered lid and the result was having to awkwardly bend it backwards or suffer a forehead or shoulder of dripping Huel. A removable lid was much simpler experience and looking at the success of Chilly’s bottles and similar we didn’t feel it a problem. We committed to producing spares just in case people lost the cap, but a bit of a straw poll of Chilly’s bottle users around the office seems none of them had ever misplaced their lids.
I would contest this since I do it most days! You can just push down the grid on top, or try with just 3 cubes if your cubes are large, your Huel will still be ice cold!
Hope some of that is helpful and that you can make the most of the nutritious Huel still in your cupboard!