Convective boundary mixing (CBM) is ubiquitous in stellar evolution. It
is a necessary ingredient in the models in order to match observational
constraints from clusters, binaries and single stars alike. We compute
`effective overshoot' measures that reflect the extent of mixing and
which can differ significantly from the input overshoot values set in
the stellar evolution codes. We use constraints from pressure modes to
infer the CBM properties of Kepler and CoRoT main-sequence and subgiant
oscillators, as well as in two radial velocity targets (Procyon A and
α Cen A). Collectively these targets allow us to identify how
measurement precision, stellar spectral type, and overshoot
implementation impact the asteroseismic solution. With these new
measures we find that the `effective overshoot' for most stars is in
line with physical expectations and calibrations from binaries and
clusters. However, two F-stars in the CoRoT field (HD 49933 and HD
181906) still necessitate high overshoot in the models. Due to short
mode lifetimes, mode identification can be difficult in these stars. We
demonstrate that an incongruence between the radial and non-radial modes
drives the asteroseismic solution to extreme structures with
highly-efficient CBM as an inevitable outcome. Understanding the cause
of seemingly anomalous physics for such stars is vital for inferring
accurate stellar parameters from TESS data with comparable timeseries
length.