Microphone goes silent during call (hardware problem)

Hi guys, I had this problem for a long time, i want to make the story very short. My microphone becomes silent after 1 minute of use. I used the stock voice recorder to check it without the need to call someone. People get annoyed because they can't speak to me. Sometimes the microphone is silent from the very beginning of a conversation. I hear them well but they can't hear me. Once i've changed the mic flex cable/usb port plate and it looked like it worked fine for about a month. Then the problem came back. Could it be the motherboard? Did anyone experience something similar? I had to repair my camera right after buying it second hand. The technician told me the phone was in touch with water after he replaced the back camera.

seeking ROM with specific reqs: no encryption and 'native' true silent mode

Hoping to pick the collective brains of XDA forum members:

Do you know of a stable, customizable, frequently updated ROM with good battery life which doesn't force encryption (although I found this in case I have to work around my encryption requirement) and has built in true silent mode? If such a thing exists, I'm all ears.

tl;dr special snowflake details:
I can't work out what benefit encryption brings me other than a performance hit, so I want to ditch it. The NSA is welcome to look through my somewhat mundane photos and documents if that is how they get their jollies.
The xposed implementation of true silent mode seems buggy when I ran it on 5.1.1 stock (sometimes volume down would make it go up, then down after a few more presses).
Having my battery last all day is pretty much my number one concern, followed by lashings of customizability.
Bonus points would be some way for me to override forced screenlock on corporate policy--as long as I can still remote wipe.

If it does all these things, has a good sense of humor and likes to take long walks on the beach, then you've found me my daily driver.

Allow calls through in silent mode after multiple calls in Lollipop?

I'm not on the Moto X anymore, but my sister is. She claims that on KitKat, she had it set so that if someone called twice in succession while in silent mode, her phone would ring for the second call. Now on Lollipop she can't find that option. Is this no longer possible, and if it is, how can she do this?