Ah, I think I may know the reason.
Disable 'normalize' in the height map export settings.
What that's doing is taking all the height values and finding their minimum/maximum and then converting the results into values ranging from 0-1. However, in a tiled setup this can mean that each tile will have a different normalization...one tile's min/max may be 0/50, another tile's min/max may be 2/47...if those mismatched min/max ranges are all converted to 0-1 values, the resulting extrusions/texmaps won't line up exactly.
If you disable that the resulting EXR values will be in real-world scale, but the tiles will line up.
In the future I may add a secondary option to 'normalize across all tiles' or something, so that normalization can be re-enabled but all tiles will be normalized together, preventing inter-tile differences.
Disable 'normalize' in the height map export settings.
What that's doing is taking all the height values and finding their minimum/maximum and then converting the results into values ranging from 0-1. However, in a tiled setup this can mean that each tile will have a different normalization...one tile's min/max may be 0/50, another tile's min/max may be 2/47...if those mismatched min/max ranges are all converted to 0-1 values, the resulting extrusions/texmaps won't line up exactly.
If you disable that the resulting EXR values will be in real-world scale, but the tiles will line up.
In the future I may add a secondary option to 'normalize across all tiles' or something, so that normalization can be re-enabled but all tiles will be normalized together, preventing inter-tile differences.