2D materials have emerged over the last decade as the new playground for quantum photonics
\r\ndevices. Among them, hexagonal boron nitride (hBN) is an interesting candidate, mainly because of its
\r\ncrystallographic compatibility with different 2D materials, but also because of its ability to harbour optically
\r\nactive defects that generate single photons. The negatively charged boron vacancy was the first intrinsic
\r\noptically addressable spin defect in hBN reported in 2020, allowing coherent control at room temperature.
\r\nAlthough other types of spin centres have been found in this material since then, this spin-1 colour centre
\r\nremains the only one with a clearly elucidated structure. Practical applications of hBN spin centres as
\r\nintrinsic magnetic field, temperature, pressure, etc. sensors in van der Waals heterostructures are hence
\r\nenvisioned. To further boost the quantum sensing applications of this spin defect in hBN, we are currently
\r\ninvestigating the dynamics of the intermediate state, also known as the metastable state, because it is likely
\r\nto trap electrons for a certain time, which affects the subsequent sensing protocol when the pulsed
\r\nmagnetic resonance experiment is designed.