Hi, I'm not entirely sure if that's even a problem with the plugin itself. Could just as well be Octoprint or the printer itself, but you gotta start somewhere.
We have an Ender 3 v2 and recently swapped out the factory bed with a magnetic one to test if that is useful at all. The issue here is that the new bed is about a third of the thickness of the factory bed.
Somehow, that leads to problems with Bed Visualizer; of course, we had to raise the bed for the printer to be able to reach it, and of course that leads to a bed that's far from leveled. But the weird thing is that the Bed Visualizer marks every part of the bed as way too high, even though it's barely high enough for the printer to reach the bed.
And that's with an offset of -4mm... The printer apparently can't get lower.
And I don't know where the issue that causes this lies; the way I see it, it should make no difference to Bed Visualizer if it's the thicker factory bed or the raised magnetic bed, as long as they're both the same height (and level, but that's a different thing).
In the end, this is not an issue that prevents us from printing, as we can just pretend that 'yellow is green'. It's mainly my inability to grasp where the issue lies that forces me to look for an answer.
Thanks in advance for the help, if there's any additional information you may need, I'd be glad to provide it to you!