I think Hitachi designed this system under license for Canon and they are both under contract. Hitachi make flashes fr most major brands, all under licence and due to specific patents owned by different brands, some feeatures or work arounds are required for each brand. Frankly it's a quagmire.
Ever since the RT range, Canon's flashes have become so expensive and overburdened, I think they have completely lost their way.
Canon seem to have really pulled back with their accessories on the R mount cameras. From grips, flashes, covers, clips or even extension tubes. There's a lot of gaps and holes in the range.