Fuzzy Union (OR)
grid_calculus
QgsProcessingParameterMultipleLayers|GRIDS|Grids|3|None|False
QgsProcessingParameterEnum|TYPE|Operator Type|[0] max(a, b) (non-interactive);[1] a + b - a * b;[2] min(1, a + b)
QgsProcessingParameterRasterDestination|OR|Union