Hole quantum dots show immense promise as spin-qubits thanks to their strong spin-orbit interaction providing all electric control. However, the spin-orbit interaction can lead to qubit operation being highly dependent on the electrostatic potential and quantum dot occupation number. In this work, we use DC transport measurements to probe the sensitivity of hole-spin properties to hole occupation number in a planar silicon double-quantum dot device fabricated on a 300 mm integrated platform. We investigate the g-tensor and spin-relaxation induced leakage current for three different hole occupation numbers within the Pauli spin-blockade regime as a function of magnetic-field orientation. We find the g-tensor and spin-leakage current to be rather insensitive to the hole number, and extract the dominant inter-dot spin-orbit coupling mechanism as surface-Dresselhaus, with an in-plane orientation deviating from the interdot axis by $\varphi$ = 2.5${}^{\circ }$. Our findings indicate that hole-spin devices are not as sensitive to precise operating conditions as anticipated which has important implications for optimizing spin control and readout based on magnetic-field direction.