You're absolutely right about that - power banks that don't have that momentary cutoff are rare and would be highly sought. However, vermaden is powering a sma

You're absolutely right about that - power banks that don't have that momentary cutoff are rare and would be highly sought. However, vermaden is powering a small form factor computer that appears to be able to take anywhere from 12 to 19 volts. This means the power is internally regulated, which means that there's at least some amount of capacitance in the regulation circuit. Many devices like these can handle a drop of power of a small fraction of a second, but likely not more. For my own SBCs, a rather large capacitor made a power bank I was using work, but the size of the capacitor was unwieldy. I'm more inclined to use an all-in-one charging and battery circuit that feeds the SBC directly. I'm surprised there isn't already a market for power banks without momentary cutoff. There's quite a market for UPS Pi hats already.