NDB approach flapless scenario

[Mach E Avelli]

I disagree that this is an unlikely scenario, as I have experienced it twice in my career; albeit without the NDB approach speed being limiting.
If you have no fuel and you are at a destination where the flaps fail, you have no choice but to carry out the best approach available to the best runway available. If that's an NDB to circle to some short strip covered in water, so be it. If you are some place that requires an NDB approach, of course the runway will be wet and it won't be grooved.
The regulations don't require you to consider flapless performance; the emergency you need to consider for planning purposes is one-engine-inoperative capability for the entire route including landing and/or missed approach.
So, keep it simple. Depending on the approach design, terrain etc, either reduce timing outbound or knock 25 knots off the recommended clean speed and restrict bank angle to 15 degrees, or do both if it is really restrictive in terms of turning radius. It won't stall unless you do something really stupid like pull 'g' while turning. Ditto if the runway is too short for a flapless landing. In the scenario, you don't have the luxury to divert so you ARE going to land. So, if the runway is less than required, kiss goodbye to the wind/gust additives to flapless Vref and fly very accurately. Dumping it on the numbers and apply aggressive braking, reverse etc will get it stopped within the confines of the runway.
Manoeuvering speeds are very conservative. Compare V2 for any flap configuration with Vman for the same flap e.g. B737 flap 1 V2 could be 155 knots at your weight but Vman typically 190, so that says you can safely pull 15 degrees of bank at 155 knots whether taking off OR approaching in that flap configuration.
Every ops manual and every state regulatory body either does state, or should state, that the Captain can step outside the rules, AFM , SOP or whatever else if necessary to save the ship.