The Malkoff web site claims 10-20 lumens on low when using the Hi/Lo switch. No specific drop-in is mentioned, but I'd strongly suspect the M60.
I haven't tried to quantify the output on low - I could do a ceiling bounce with an M61LL & an M30, but it won't happen right away.
I'm particularly interested in how the M31 behaves with a Hi/Lo switch when powered by 2x AA NiMh or 2x AA Lithium. I'll be checking that when my M31s arrive.
In my case, my M6xLL modules live in Surefire G3 hosts, so no Hi/Lo in normal use. This is because the intended application does not require an extremely low output, and I have other lights that do provide ELO for applications that require it.
<EDIT> Gene has been known to do a custom resistor value in the past, if you're trying to hit a specific output. That doesn't guarantee that you'd be able to get one now, as it's not an advertised item. It wouldn't be too difficult to do a custom value by modifying a switch you already own.
- Syncytial.