  We investigate outflows and the physics of super-Eddington versus
sub-Eddington regimes in black hole systems. Our focus is on prospective
science using next-generation high-resolution soft X-ray instruments. We
highlight the properties of black hole ultraluminous X-ray source (ULX) systems
in particular. Owing to scale invariance in accreting black holes, ULX
accretion properties including their outflows, inform our understanding not
only of the closely-related population of (similar-mass) X-ray binary systems,
but also of tidal disruption events (TDEs) around supermassive black holes. A
subsample of TDEs are likely to transcend super-Eddington to sub-Eddington
regimes as they evolve, offering an important unifying analog to ULXs and
sub-Eddington X-ray binaries. We demonstrate how next-generation soft X-ray
observations with resolving power > 1000 and collecting area > 1000 cm^2 can
simultaneously identify ultrafast and more typical wind components, distinguish
between different wind mechanisms, and constrain changing wind properties over
characteristic variability timescales.
