If you're worried about voltage drop out have you ever thought of making a Sepic converter, they'll even step up once the voltage goes under the output setpoint.
Yes, I've heard of those but try building one without a specialised IC.
Another option is to use a transformer rather than an inductor.
Like lots of the circuits I think of, I'll probably never use it. I thought this one was more useful than half the crap my brain generates so I thought I'd post it in case someone else finds it useful.
A typical switching regulator has a separate oscillator from the control loop because that design is too sensitive to the characteristics of the output capacitor.
Put a microhenry of ESL into the 100uF capacitor and you'll see what I mean.
Just tried that, it still works but there's much more ripple on the output, still I doubt you'll get that much ELS on a 100:mu:F capacitor, I would say 200nH is more reasonable.
It's a typical hysteric converter so yes it can be unstable
I was looking at the collector of the switching transistor and was concerned that the switching frequency went from 30 kHz to 50 MHz. Was wondering if this is real and how my ham neighbor on 6 meters would feel about it. I guess it would have to be really well shielded.