Can the 'Enable-pin' be unused / undefined

[devarishi7]

Question is actually quite simple. I am a tad short on pins in my current project, and using 1 dmx port for output only i have it hardwired to do exactly that. Now i wasn't using GPIO39 so i defined that as the enable pin, but then i had no output. Took me a while to figure that out. Sure it's input only but i was using it as a dummy. Found that using GPIO20 does work, but that pin isn't even exposed. I was just wondering if i can tell the library just not to use any enable pin.