Can the measured thrust of a propeller be greater than the maximum possible thrust predicted by Froude's Propeller Theory?
It might seem incredible but the answer looks to be: yes it can.
"Stoddard  reports measured values of the thrust which exceed the theoretical upper limit as predicted by the momentum theory by 20% to 50%."
Source: ON THE LIMITATIONS OF FROUDE'S
ACTUATOR DISC CONCEPT,
G.A.M. VAN KUIK. page 7.
"For the propeller flow the momentum theory underestimates the induced velocity, while for the wind turbine flow this is overestimated. As the induced velocity has a different sign in both flow regimes, the total velocity at the disc $u_d = U_0 + u_i$ is underestimated in all flow states: the mass flow through the rotor is always higher than predicted by the classical momentum theory."
Source: the same paper as above.