AFAIK the problem is not LSPosed itself because LSPosed doesn't show an app in the app list so it can't be detected by normal means. (To run the LSPosed GUI you have to either use the action button on the persistent notification or dial ##LSPOSED## in your phone app; or the GUI can create a launcher shortcut for you.)

The problem is that the LSPosed modules are normal apps that can be detected. So if they see something like GravityBox or XPrivacy installed it's pretty easy to figure out that you must be using Xposed/LSPosed.

I use TB Checker and it seems to be aware of most of the LSPosed modules I have installed (the above and also AFWall, Secure Settings, UpdateLocker), even of a Sony-specific module (Physical Button Master Control). It doesn't detect a couple of modules (Undo and BubbleUPnP Audio Cast) but I think the others are enough to conclude I have rooted the device. 😃

So to sum up you don't need to hide root anymore because Magisk takes care of that, and you don't need to hide LSPosed either. You can use the Hide module to hide LSPosed modules. But I would avoid doing it until all else fails for a specific app.

Obligatory note, if you add an app to the Magisk deny list it won't detect anything that has to do with Magisk but you won't be able to apply LSPosed to it so it will see the LSPosed modules.