Stardock have released a new WindowBlinds beta update which includes fixes for the Opus-related issues which were mentioned here recently.
Here's their page with the full list of changes and download links for registered WindowBlinds users:
Many thanks to Stardock for the heads-up, and for the fixes as well, of course.
(I've also updated the previous post, but I thought it best to post a new headline so more people know that the update is available.)
The recent Opus 10.0.3.1 beta also included some fixes/workarounds for cosmetic issues on our side, so these two updates (or later versions) are best used together.