6.5/6.1 4-Digit Lock Screen Code, Can We Edit To Accept Single Digit?

[BPFerrari1]

For the 6.5, or even 6.1 for that matter, we are able to use the lock-screen function with the simple 4-digit code. Is there a way we could edit that to accept, say, anything less than 4. I wanted to set it at '0' as sort of an extra step, but a very simple extra step.

Reason I ask is that with DeviceLock, I have to slide it twice before it fully unlocks my device. I slide it, it unlocks and in a matter of seconds it relocks and I have slide it again to unlock it for good. I asked and it doesn't seem anyone else is having this issue or knows of a fix.