To me post cycle recovery means recovery of gonadal function. This implies a return of total testosterone to normal pre-cycle levels. Estrogen increases sex hormone binding globulin, preventing free testosterone levels from reaching the point where they themselves impede recovery. Conversely, taking an aromatase inhibitor post cycle keeps SHBG artificially low, in turn making free testosterone artificially high. As stated, this elevated free test will act back on the HPTA to slow recovery.
That's my theory anyway, based on bloodwork readings that guys have sent me who used AI's post cycle and were having terrible recoveries.
I'd stick with SERMs. We have numerous posts here about possible actions they may exert (eg increasing pituitary GnRH receptor density) beyond their ability to block estrogen related negative feedback.