Hello Wisom-! I assume Dungeon Architect is what you are using? It is certainly an impressive piece of kit and I think it should work really well together with ATBTT. I was actually working on a dungeon generator as a side project a while back, but scrapped it once I saw Dungeon Architect. I don’t understand everything in you question (spawning the gird manager tile by tile), but I’ll tell you what I would do if I wanted to get ATBTT and Dungeon Architect working together.
I would run the dungeon generation code before activating any nodes in BP_GridManager. Then in BP_GridManager at the very beginning (of the construction script or the event graph depending on you want to pregenerate dungeons or not) I would calculate the bounds of the generated dungeon (I don’t know enough about Dungeon Architect to say what would be the best way of finding this) and set GridSizeX, GridSizeY and the heightmap cutoff point (unless you want a flat dungeon) as well as the location of the grid manager based on these bounds. Basically GridSize X would be the size of the dungeon bounds along the X axis divided by the width of your tiles. You would of course also need to set DungeonArchitect and the grid manager up so that they use grid squares of identical size.
You would have to make sure that only meshes you intend the player to walk on block PathTrace and that any meshes you do not want units to attack through block RangeTrace. I would change the Trace for Walls functions to the way it is set up in my previous post, including adding a new WallTrace channel that should be blocked by any meshes you do not want units to walk through.
At this point you should enable line trace based heightmap generation in the public variables of BP_GridManager, check Trace for Walls and ATBTT should hopefully be able to procedurally build a walkable grid on top of any dungeon Dungeon Architect can generate. This should even work for dungeons with an arbitrary number of overlapping levels, thanks to my line trace based heightmap generation.
I’ve wanted to test this out myself for some time, so let me know how it works out!