Is it possible to complete 'Underground Undercover' without 'Synth Retention'?

I'm on my first play-through (so, please no spoilers). My character is through-and-through a Railroad agent and believes in Synth Rights (this is a role-playing game, after all).

I find it, from a role-playing perspective, problematic that my character has to

capture a synth who wants to live in a raider group

in order to proceed with the Railroad and

free all synths from the Institute.

But when I try to complete 'Underground Undercover' at some point Z1 asks me to

continue to work with Father for now.

And there is only one option to doing so: 'Synth Retention' -- Which I refused to complete before as it would be out-of-character.

Am I overlooking a path?

Solution 1:

Actually Synth Retention is one of the steps in completing Underground Undercover

http://fallout.wikia.com/wiki/Underground_Undercover

The link above shows all the events that happens leading to the completion of the entire quest line, so essentially the answer is no, you must do the Synth Retention step in order to finish the quest line