Generating Bessel beams with tunable propagation lengths offers new flexibility for ultrafast laser material processing. In this work, we present a compact, integrated and adjustable diffractive optical module capable of producing a femtosecond Bessel beam whose non-diffracting zone can be continuously adjusted over nearly two orders of magnitude, from 80 µm to 1.5 mm in air, offering depths exceeding 2 mm inside borosilicate glass. A key feature of this diffractive axicon-based design is the preservation of a constant 2 µm central core diameter across the entire tuning range, ensuring stable energy confinement regardless of the selected interaction length. All optical components are fabricated in fused silica, providing full compatibility with ultrashort pulse regimes. Experiments were conducted using a Yb-based femtosecond laser (Light Conversion Carbide CB3, 1030 nm, 200 fs, up to 80 W average power). We demonstrate the versatility of this approach through single-pass cutting of borosilicate glass, showing that the volume of laser-modified material scales predictably with the programmed Bessel beam length. This direct control over the axial energy deposition profile enables precise matching to target cutting depths or internal structuring geometries, without iterative parameter optimization or hardware reconfiguration. Our results highlight the potential of integrated, adjustable Bessel optics to advance laser micromachining by combining sub-micrometric lateral precision with a dynamically reconfigurable axial interaction length, opening practical pathways toward versatile single-platform processing of substrates with varying thickness.