Fatty acyl-coenzyme A (CoA) diphosphatase that hydrolyzes fatty acyl-CoA to yield acyl-4'-phosphopantetheine and adenosine 3',5'-bisphosphate (By similarity). Preferentially hydrolyzes unsaturated long-chain acyl-CoA substrates in the endoplasmic reticulum (ER) lumen (By similarity). This catalytic activity is required for maintaining ER structure and for lipid droplets (LDs) biogenesis, which are lipid storage organelles involved in maintaining lipid and energy homeostasis (By similarity). May directly bind to diacylglycerol (DAGs) and triacylglycerol, which is also important for LD biogenesis (By similarity). May support directional budding of nacent LDs from the ER into the cytosol by reducing DAG levels at sites of LD formation (By similarity). May play a role in the regulation of cell morphology, ER morphology and cytoskeletal organization (By similarity). an acyl-CoA + H2O = adenosine 3',5'-bisphosphate + an acyl-4'-phosphopantetheine + 2 H(+) Belongs to the FIT family. FIT2 subfamily.