I've installed edp17 version twice without any issues on my Nexus 5 16GB version with multirom and used until two months ago because the cellular antenna broke.
It is a really nice build where everything works except video recording and Bluetooth calls (android support too, without camera support).
So, it seems really strange that you can't manage to install it.
What's the android rom you are using as primary? CM 12.1 same as the one used for Sailfish base?