This is all theoretical, i.e. I haven't tested it out yet; it just seems like it might work, though.
An RNLD is basically many short naps in quick succession until you're body becomes accustomed to slipping in and out of physical awareness. I'm guessing by the time you achieve SP in under 2 minutes (nano/micro-naps), you should try to LD. Thanks to neuroplasticity spending maybe one afternoon should get the ball going. Eventually (this is still all in theory), you will be able to WILD in a matter of seconds, after a lot of practice.