I ended up buying the bar clamp one once I found out I couldn’t get i-spec B for a long time. Alongside my SLX brakes it fits fairly well for single finger braking for me, where I had my (SRAM) shifters inboard before. I was also turned off by the indicator window and I don’t use it.
So although I’d still be keen to get rid of the indicator window and try it inboard once I can get the blanking plate, I’m not all that bothered now it’s installed.
Interesting that that German site now seems to have the blanking plate but it seems overkill to order something so tiny from Germany. Maybe worth ordering a job lot of them between a few mates. Do they definitely have them in stock?