  Chevron rollovers of some proteins imply that their logarithmic folding rates
are nonlinear in native stability. This is predicted by lattice and continuum
G\=o models to arise from diminished accessibilities of the ground state from
transiently populated compact conformations under strongly native conditions.
Despite these models' native-centric interactions, the slowdown is due partly
to kinetic trapping caused by some of the folding intermediates' nonnative
topologies. Notably, simple two-state folding kinetics of small single-domain
proteins are not reproduced by common G\=o-like schemes.
