As promised, today a new version of the app has been released with the new feature of configurable swipe actions for posts/comments/mentions/replies, plus a couple of minor fixes and improvements according to your suggestions.
I’ve already been receiving some reports and we have an improved German translation thanks to reusityback so expect a .1 patch soon.
You can make it sticky by disabling the edge-to-edge option im settings but that’s not what you are asking. And you are right, the change has been introduced recently starting with version 1.5.3.
A proper way to solve this would be to add another option if edge-to-edge display is enabled, to make it not completely transparent but with just some alpha.