  We investigate the effect of observing cadence on the precision of radius
ratio values obtained from transit light curves by performing uniform Markov
Chain Monte Carlo fits of 46 exoplanets observed by the Transiting Exoplanet
Survey Satellite (TESS) in multiple cadences. We find median improvements of
almost 50% when comparing fits to 20s and 120s cadence light curves to 1800s
cadence light curves, and of 37% when comparing 600s cadence to 1800s cadence.
Such improvements in radius precision are important, for example, to precisely
constrain the properties of the radius valley or to characterize exoplanet
atmospheres. We also implement a numerical Information Analysis to predict the
precision of parameter estimates for different observing cadences. We tested
this analysis on our sample and found it reliably predicts the effect of
shortening observing cadence with errors in the predicted % precision of <0,5%
for most cases. We apply this method to 157 TESS object of interest that have
only been observed with 1800s cadence to predict the precision improvement that
could be obtained by reobservations with shorter cadences and provide the full
table of expected improvements. We report the 10 planet candidates that would
benefit the most from reobservations at short cadence. Our implementation of
the Information Analysis for the prediction of the precision of exoplanet
parameters, Prediction of Exoplanet Precisions using Information in Transit
Analysis (PEPITA) is made publicly available.
