Hello there, it's a pleasure to greet you!
The issue you're encountering seems to involve errors from other users' plugins. Please take a look at the log from the screenshot you sent me; you'll notice that there is no mention of any lines from my plugin. It appears to be primarily an incompatibility between VisuStella's Core and SUM's HUD maker.
It's challenging to work on a scenario that I'm not familiar with, as each author has their own functions and ways of doing things. Personally, I always work based on RPG Maker MZ vanilla, as it's the cleanest way to go about it.
I'm not sure how I can assist you with this, as it sounds like an issue related to how SUM is obtaining information. In my case, information is typically stored in the game's variables, so you should be able to use it normally within the scope of the map (Scene_Map).