Those are most likely not in high frequency paths, where you need low esr, so it doesn't really matter. But I'd expect 4-10 ohm for such capacitors.
For example, you may see such small capacitor on the input of a controller chip, to smooth out the input voltage before the chip gets its power from an auxiliary winding on the transformer. don't need low esr for that. [...]
I find the SMPS aux cap must be low ESR. They are typically 10-47uF and commonly fail, I think because the parts see high ripple current spikes with the drive switching on the mosfet. I'm not sure, they simply fail a lot. Some SMPS add a small series resistor like 10Ω feed in series with the cap after the rectifier diode.
47uF 50V ripple current spec. 100kHz varies from is 90-400mA, depending on the part. For the better parts:
Nichicon
UPW 300mA at 100kHz, ESR 0.43Ω
Panasonic
FR 405mA at 100kHz, ESR 0.14Ω