Am I over complicating...simplified expenses........

After focusing on lots of 12/13 work I find myself a bit confused by some of the HMRC guidance on the new simplified expenses for 13/14. In short are those sole traders who don't use the cash basis still able to claim 45p per mile to keep things simple?

HMRC March tech note says ref' simplified expenses- "they are entirely optional for those using the cash basis and for those outside the cash basis."

Does this mean that simplified expenses (business mileage 45p, home use) can still be used if not doing the cash basis? Also use of home seems to start at 25 hours per month, a bit harder to justify for some.

Thoughts appreciated.