Usually missions like Kepler are finding exoplanets orbiting (the barycenter of systems related to...) stars at distances that are not common if compared with the Solar System. This finding (as I understand) motivate models in which migration of planets is involved as hypothesis, due to torques (e.g., Lindblad and Co-rotation) and angular momentum exchange.
In this context I ask myself the following hypothetical question: if any exoplanet detection mission (or other related works) find low orbital period planets (e.g., warm Jupiters) orbiting a stellar black hole, would this be (although indirect) "key" evidence of migration processes? (as a star becoming a BH should drag any planet that is close enough, when it collapses)
As new telescopes are being developed, how "far" are we from detecting scenarios such as planets orbiting black holes? It could sound really hard (maybe impossible) to detect a signal of transit or RV without a star emitting light towards us that could reveal motion or a significant drop in the relative flux. Also, mass ratios might complicate this even more but, are there any other possibilities? (High energy doppler? Microlensing? direct imaging?, a system involving also a binary star?, ...)