you will see that opinions vary widely on mass. There is probably some degree of logic in assuming the planet is rocky and earthlike in composition but a water planet or iron core planet would skew the mass greatly.

Some of the guesstimates say the gravity could be up to 10G for K62F. There is also a strong faction that believes the Goldilocks super-Earths will be water planets

All of the speculation is clear that they don't have the ability to determine the make up of the exo-planets in order to accurately figure mass. The next generation of planet finders will probably have that capability.

I should have linked the site that said 1.4 but they didn't support the number in any way so it isn't that important.