The problem is a moderate repeatability.
A little amount of triethylamine increases polarity that helps a better separation; but it simultaneously increases the dielectric constant of the solvent that might lead to partial and random coagulation of silica particles due to electrostatic forces.
Furthermore, triethylamine is rarely free of water traces and as a consequence, a little but significant amount of silica might be dissolved. Thus, a better separation might be achieved, but with moderate repeatability due to the random coagulation and sedimentation of silica particles in the column.
All above is not important, regarding TLC monitoring but it is quite important, regarding the validity of a scientific work and very important, regarding a patent’s validity.