We presented a study on MFU-4 and its isostructural analogue MFU-4-Br as versatile metal-organic frameworks with adjustable pore apertures. These MOFs, composed of benzobistriazole ligands, Zn II cations, and halide side ligands, exhibit large voids and narrow pore openings, offering potential for customizable guest trapping. Gas loading experiments involving xenon and krypton illustrate the impact of the guest-pore aperture size ratio on gas uptake, with higher ratios requiring elevated temperatures for efficient loading. The experimental determination of activation energy for gas release underscores the significance of this ratio. Moreover, the investigation into gas release kinetics over time, particularly under ambient conditions, offers valuable insights into the long-term gas storage and practical applicability of these MOFs. The gradual release of gases, notably observed in xenonloaded MFU-4 and MFU-4-Br, highlights the potential for controlled gas storage and release, beneficial for various gas capture and delivery applications. Computational studies further validate these findings, offering insights into the gas diffusion mechanisms within the MOF structures.