No, the adapter sleeve is not a good solution for the stem spacer rings. If you look closely at the threadless headset, the top bearing has a thin wedge that needs to be pushed down by the stem spacers. That floating sleeve inside won’t press down on the wedge. If you are lucky the 11/8 spacer might contact the wedge sufficiently. But I don’t like to rely on luck.
you can easily find 1” stem spacers on ebay:
https://www.ebay.com/itm/292400422820