For single events, having the voltage bounded is better than unbounded; the ripple margin doesn't really matter. Ok, the opto might not be happy with a 17V excursion.
Want to say I've seen much less than 3 ohms ESR for 100uF range capacitors. That's still possible under low temperatures or aged conditions (dried out cap) though. But such conditions don't really have an endpoint, so to address those failure modes, you'd have to use something other than electrolytic, entirely.
Even against 10m of wire, you'll have maybe 6uH stray inductance, which will ring with 0.1uF at 200kHz (Zo = 7.7 ohm), and with 100uF at 6.5kHz (Zo = 0.25 ohm). Since ESR > 0.25 ohm, in series, the supply inrush/transient response will be well damped, so that's good. With ESR < 7.7 ohm, in parallel, inrush/transient to the small bypass cap will also be well damped. So at least there won't be ringing and squigglies due to that.
Ripple current rating won't matter to non-repetitive events, of course. The supply becomes substantially resistive above 6kHz (where 10m of cable begins to act rather inductive), so any switching above 6kHz will be carried more and more by the cap, and the ripple rating will need to be observed.
So, somewhere around the 1kHz-50kHz range, depending on cable length and attached capacitance, will be the crossover range where the local cap matters.
Tim