I have low power mode more or less working - and I believe the wifi config interface will work and activate if the module cannot get an IP. For low power mode I am using node.dsleep(). It's working as far as I can tell, but I can't get the red LED to go out so I'm not sure how much power it is saving.
I've update github with working code for low power mode.
I also ordered a nodemcu board from ebay to test. It cost around $7 w/shipping.