Hall effect - inapplicability to low mobility materials

Here is what I think why Hall effect is inapplicable for charge carrier mobility measurements in low mobility semiconductors:

1.    The problem is that low drift velocity does not generate large enough magnetic force. Lorentz force is many orders of magnitude weaker than the force created by an electric field. Therefore, charge carrier deflection with magnetic field is very weak. Also, all sorts of interfacial fields and local fields due to grain boundaries will dominate over the Lorentz force and will disturb the measurement. We want Lorentz force to be comparable to force of e-field, F_B / F_E > 1, or e*v*B / e*E = v*B / E = mu*E*B / E = mu*B > 1. I like this explanation because it so obvious that with practically achievable magnetic fields (~10T) we need mobility to be > 0.1 m2/Vs or > 1000 cm2/Vs. This is never the case in disordered semiconductors.
2.    Hall voltage (or e-field) is very small. E_hall = v * B, with typical mu=1e-10 m2/Vs and strong e-fields E=1e8 V/cm, we have a drift velocity v=0.01 m/s only. Then the largest experimentally measurable Hall voltage is E_hall = 0.01 m/s * 10 Tesla = 0.1 V/m. This is really difficult to measure.
3.    Its interesting to note that Hall voltage is independent on carrier concertation (doping, injection levels etc.), E_Hall = R_Hall * J_injection * B (Hall coefficient R_Hall contains density and injection current J_inject contains density therefore it cancels out).