stepwise_jitter should be deprecated regardless.
delta, gamma, kappa, and t0 configure the dual averaging of the integrator step size. The last three probably shouldn’t be touched by anyone not heavily versed in Nesterov optimization theory, but delta defines the target adaptation stat and would nominally be exposed in case of divergences. That said, it might be easier to avoid delta entirely and have users set the step size themselves (without the adaptation being able to change it).
mass matrixinv_metric, init_buffer, term_buffer, and window configure the adaptation of the inverse metric elements. It’s not that these shouldn’t be exposed to the user but rather that they should be exposed only in certain patterns. For example if a user wants to specify their own inverse metric components and not allow them to be changed then they might call something like adaptation=static_inv_metric or something where inv_metric is set and window is forced to zero at the same time.