The first case/cover I gave my Mum for her Kobo Touch held the reader in with the same type of bands and she had to slip the band off the right corner to use her on/off slider. Really annoyed her. I bought her a new cover which you slid the reader into the cover and it left all the buttons/ports available. She much prefers it.
Given that experience, I found I couldn't get my fingers to work the slider with the older case, I avoid buying case which hold the reader in with corner bands now myself.
But like you said it will do until you get an actual Kobo cover fitted for it alone. I'm doing the same, but using a neoprene sleeve to protect my Glo, until I find a case/cover to my taste.