Energy efficient inrush current limiting
Let me hazard a proper response... in what way is a P-FET not applicable, due to bidirectional operation?
To formulate this more specifically: while recuperating, do you need to impose a current limit (prevent inrush) as well, in the reverse direction? Or do you merely believe, that a P-FET does not conduct in the reverse direction? (you'd be wrong about that) Do you need to consider the scenario, where the DC rail switch gets flipped ON while already recuperating ?  Implementing a bidirectional limit would require two FET switches in series and a bipolar threshold detector. Not impossible but would complicate things a little.
I've been toying with the idea for a while, to build a FET-based current limiter gadget, probably for the range of single ampers of working current. To extend the idea to a couple dozen amps, you'd have to use larger FET's / several of them connected parallel (and matched for linear operation!) but otherwise it's probably just a matter of dimensioning for the current and for the energy capacity required (and dimensioning the linear drivers perhaps, to assure fast response in the FETs).