suggestion for kobo cover

I recently replaced my kobo mini with kobo clara hq.
I diy my own sleep cover for my clara hq.
In designing the diy sleep cover, I wondered why kobo did not design a kobo case that could attach the screen cover only.
The only screen cover will reduce the weight and exposure the nice design non-slip back of the reader. In order for attaching the screen cover, the design of the reader has to be modified.
Looking for a better design kobo superior to others.