  Near-term studies of Venus-like atmospheres with JWST promise to advance our
knowledge of terrestrial planet evolution. However, the remote study of Venus
in the Solar System and the ongoing efforts to characterize gaseous exoplanets
both suggest that high altitude aerosols could limit observational studies of
lower atmospheres, and potentially make it challenging to recognize exoplanets
as "Venus-like". To support practical approaches for exo-Venus characterization
with JWST, we use Venus-like atmospheric models with self-consistent cloud
formation of the seven TRAPPIST-1 exoplanets to investigate the atmospheric
depth that can be probed using both transmission and emission spectroscopy. We
find that JWST/MIRI LRS secondary eclipse emission spectroscopy in the 6 $\mu$m
opacity window could probe at least an order of magnitude deeper pressures than
transmission spectroscopy, potentially allowing access to the sub-cloud
atmosphere for the two hot innermost TRAPPIST-1 planets. In addition, we
identify two confounding effects of sulfuric acid aerosols that may carry
strong implications for the characterization of terrestrial exoplanets with
transmission spectroscopy: (1) there exists an ambiguity between cloud-top and
solid surface in producing the observed spectral continuum; and (2) the
cloud-forming region drops in altitude with semi-major axis, causing an
increase in the observable cloud-top pressure with decreasing stellar
insolation. Taken together, these effects could produce a trend of thicker
atmospheres observed at lower stellar insolation---a convincing false positive
for atmospheric escape and an empirical "cosmic shoreline". However, developing
observational and theoretical techniques to identify Venus-like exoplanets and
discriminate them from stellar windswept worlds will enable advances in the
emerging field of terrestrial comparative planetology.
