Yeah, the coloir change does waste a lot of filament. It's the same with any machine that uses a single nozzle for multiple colours / materials. If you want less waste then you need a toolchanger or an IDEX.
I have a Toolchanger and it's great when it works. Pain in the ass to deal with though.
My main reason for having this though is not multi-colour prints. It's to have 4 different filaments loaded and being able to choose at the time I send the print job what to print it with rather than having to go and unload / load filiament.
At the moment I've got it loaded with PLA, PETG, ASA, and soluable support material. I think that's what it will be set up with going forwards.