RADIATION: Total-Body Irradiation

DRUG: Thiotepa

DRUG: Fludarabine

DRUG: Cyclophosphamide

DRUG: Busulfan

PROCEDURE: Allogeneic Bone Marrow Transplantation

DRUG: Tacrolimus

DRUG: Methotrexate

PROCEDURE: Naive T Cell-Depleted Hematopoietic Stem Cell Transplantation

PROCEDURE: Echocardiography

PROCEDURE: Biospecimen Collection

PROCEDURE: Bone Marrow Aspiration

PROCEDURE: Bone Marrow Biopsy

DRUG: Bezuclastinib Tablets (Formulation A)

DRUG: Bezuclastinib Tablets (Formulation B)

DRUG: Placebo Tablets

DRUG: Avapritinib

DRUG: Decitabine

COMBINATION_PRODUCT: Decitabine/Cedazuridine

DRUG: Elenestinib

DRUG: Placebo

DRUG: BLU-263

DRUG: Azacitidine

DRUG: bezuclastinib

DRUG: TL-895

DRUG: Placebo

DRUG: MGD024