[Android Q&A, Help & Troubleshooting] SpasilliumNexus:
EDIT: Nevermind. I found a solution.

I've been searching non-stop for almost 2 days using different search terms and am at a total loss here.

What I am trying to do is have my addon.d script comment out a few lines (lines 32 to 38) upon flashing a CM12 ROM update in audio_policy.conf (in red bold.)

# Global configuration section: lists input and output devices always present on the device
# as well as the output device selected by default.
# Devices are designated by a string that corresponds to the enum in audio.h

global_configuration {
attached_output_devices AUDIO_DEVICE_OUT_EARPIECE|AUDIO_DEVICE_OUT_SPEAKER|AUDIO_DEVICE_OUT_TELEPHONY_TX
default_output_device AUDIO_DEVICE_OUT_SPEAKER
attached_input_devices AUDIO_DEVICE_IN_BUILTIN_MIC|AUDIO_DEVICE_IN_BACK_MIC|AUDIO_DEVICE_IN_REMOTE_SUBMIX|AUDIO_DEVICE_IN_VOICE_CALL|AUDIO_DEVICE_IN_TELEPHONY_RX
}

# audio hardware module section: contains descriptors for all audio hw modules present on the
# device. Each hw module node is named after the corresponding hw module library base name.
# For instance, "primary" corresponds to audio.primary.<device>.so.
# The "primary" module is mandatory and must include at least one output with
# AUDIO_OUTPUT_FLAG_PRIMARY flag.
# Each module descriptor contains one or more output profile descriptors and zero or more
# input profile descriptors. Each profile lists all the parameters supported by a given output
# or input stream category.
# The "channel_masks", "formats", "devices" and "flags" are specified using strings corresponding
# to enums in audio.h and audio_policy.h. They are concatenated by use of "|" without space or "\n".

audio_hw_modules {
primary {
outputs {
primary {
sampling_rates 44100|48000
channel_masks AUDIO_CHANNEL_OUT_STEREO
formats AUDIO_FORMAT_PCM_16_BIT
devices AUDIO_DEVICE_OUT_EARPIECE|AUDIO_DEVICE_OUT_SPEAKER|AUDIO_DEVICE_OUT_WIRED_HEADSET|AUDIO_DEVICE_OUT_WIRED_HEADPHONE|AUDIO_DEVICE_OUT_ALL_SCO|AUDIO_DEVICE_OUT_AUX_DIGITAL|AUDIO_DEVICE_OUT_PROXY
flags AUDIO_OUTPUT_FLAG_PRIMARY
}
[B][COLOR="Red"] deep_buffer {
sampling_rates 8000|11025|12000|16000|22050|24000|32000|44100|48000
channel_masks AUDIO_CHANNEL_OUT_STEREO
formats AUDIO_FORMAT_PCM_16_BIT
devices AUDIO_DEVICE_OUT_EARPIECE|AUDIO_DEVICE_OUT_SPEAKER|AUDIO_DEVICE_OUT_WIRED_HEADSET|AUDIO_DEVICE_OUT_WIRED_HEADPHONE|AUDIO_DEVICE_OUT_ALL_SCO|AUDIO_DEVICE_OUT_AUX_DIGITAL|AUDIO_DEVICE_OUT_PROXY
flags AUDIO_OUTPUT_FLAG_DEEP_BUFFER
}[/COLOR][/B]
multichannel {
sampling_rates 8000|11025|12000|16000|22050|24000|32000|44100|48000|96000
channel_masks dynamic
formats AUDIO_FORMAT_PCM_16_BIT
devices AUDIO_DEVICE_OUT_AUX_DIGITAL|AUDIO_DEVICE_OUT_PROXY
flags AUDIO_OUTPUT_FLAG_DIRECT
}
compress_offload {
sampling_rates 8000|11025|16000|22050|32000|44100|48000|64000|88200|96000|176400|192000
channel_masks AUDIO_CHANNEL_OUT_MONO|AUDIO_CHANNEL_OUT_STEREO|AUDIO_CHANNEL_OUT_2POINT1|AUDIO_CHANNEL_OUT_QUAD|AUDIO_CHANNEL_OUT_PENTA|AUDIO_CHANNEL_OUT_5POINT1|AUDIO_CHANNEL_OUT_6POINT1|AUDIO_CHANNEL_OUT_7POINT1
formats AUDIO_FORMAT_MP3|AUDIO_FORMAT_AAC_LC|AUDIO_FORMAT_AAC_HE_V1|AUDIO_FORMAT_AAC_HE_V2|AUDIO_FORMAT_MP2|AUDIO_FORMAT_PCM_16_BIT_OFFLOAD|AUDIO_FORMAT_PCM_24_BIT_OFFLOAD
devices AUDIO_DEVICE_OUT_SPEAKER|AUDIO_DEVICE_OUT_EARPIECE|AUDIO_DEVICE_OUT_WIRED_HEADSET|AUDIO_DEVICE_OUT_WIRED_HEADPHONE|AUDIO_DEVICE_OUT_ALL_SCO|AUDIO_DEVICE_OUT_AUX_DIGITAL
flags AUDIO_OUTPUT_FLAG_DIRECT|AUDIO_OUTPUT_FLAG_COMPRESS_OFFLOAD|AUDIO_OUTPUT_FLAG_NON_BLOCKING
}
voice_tx {
sampling_rates 8000|16000|48000
channel_masks AUDIO_CHANNEL_OUT_STEREO|AUDIO_CHANNEL_OUT_MONO
formats AUDIO_FORMAT_PCM_16_BIT
devices AUDIO_DEVICE_OUT_TELEPHONY_TX
}
voip_rx {
sampling_rates 8000|16000
channel_masks AUDIO_CHANNEL_OUT_MONO
formats AUDIO_FORMAT_PCM_16_BIT|AUDIO_FORMAT_AMR_NB|AUDIO_FORMAT_AMR_WB|AUDIO_FORMAT_QCELP|AUDIO_FORMAT_EVRC|AUDIO_FORMAT_EVRCB|AUDIO_FORMAT_EVRCWB|AUDIO_FORMAT_EVRCNW
devices AUDIO_DEVICE_OUT_SPEAKER|AUDIO_DEVICE_OUT_EARPIECE|AUDIO_DEVICE_OUT_WIRED_HEADSET|AUDIO_DEVICE_OUT_WIRED_HEADPHONE|AUDIO_DEVICE_OUT_ANLG_DOCK_HEADSET|AUDIO_DEVICE_OUT_DGTL_DOCK_HEADSET|AUDIO_DEVICE_OUT_ALL_SCO
flags AUDIO_OUTPUT_FLAG_DIRECT|AUDIO_OUTPUT_FLAG_VOIP_RX
}
}
inputs {
primary {
sampling_rates 8000|11025|12000|16000|22050|24000|32000|44100|48000
channel_masks AUDIO_CHANNEL_IN_5POINT1|AUDIO_CHANNEL_IN_MONO|AUDIO_CHANNEL_IN_STEREO|AUDIO_CHANNEL_IN_FRONT_BACK
formats AUDIO_FORMAT_PCM_16_BIT|AUDIO_FORMAT_AMR_NB|AUDIO_FORMAT_AMR_WB|AUDIO_FORMAT_QCELP|AUDIO_FORMAT_EVRC|AUDIO_FORMAT_EVRCB|AUDIO_FORMAT_EVRCWB|AUDIO_FORMAT_EVRCNW
devices AUDIO_DEVICE_IN_BUILTIN_MIC|AUDIO_DEVICE_IN_WIRED_HEADSET|AUDIO_DEVICE_IN_BLUETOOTH_SCO_HEADSET|AUDIO_DEVICE_IN_BACK_MIC|AUDIO_DEVICE_IN_VOICE_CALL
}
voice_rx {
sampling_rates 8000|16000|48000
channel_masks AUDIO_CHANNEL_IN_STEREO|AUDIO_CHANNEL_IN_MONO
formats AUDIO_FORMAT_PCM_16_BIT
devices AUDIO_DEVICE_IN_TELEPHONY_RX
}
}
}
a2dp {
outputs {
a2dp {
sampling_rates 44100
channel_masks AUDIO_CHANNEL_OUT_STEREO
formats AUDIO_FORMAT_PCM_16_BIT
devices AUDIO_DEVICE_OUT_ALL_A2DP
}
}
}
usb {
outputs {
usb_accessory {
sampling_rates 44100
channel_masks AUDIO_CHANNEL_OUT_STEREO
formats AUDIO_FORMAT_PCM_16_BIT
devices AUDIO_DEVICE_OUT_USB_ACCESSORY
}
usb_device {
sampling_rates 44100
channel_masks AUDIO_CHANNEL_OUT_STEREO
formats AUDIO_FORMAT_PCM_16_BIT
devices AUDIO_DEVICE_OUT_USB_DEVICE
}
}
}
r_submix {
outputs {
submix {
sampling_rates 48000
channel_masks AUDIO_CHANNEL_OUT_STEREO
formats AUDIO_FORMAT_PCM_16_BIT
devices AUDIO_DEVICE_OUT_REMOTE_SUBMIX
}
}
inputs {
submix {
sampling_rates 48000
channel_masks AUDIO_CHANNEL_IN_STEREO
formats AUDIO_FORMAT_PCM_16_BIT
devices AUDIO_DEVICE_IN_REMOTE_SUBMIX
}
}
}
}

I've came across a few solutions, but none of them worked -> except the one I found here which was the closest to working <-

sed -i '32 s/^/#/' /system/etc/audio_policy.conf;
sed -i '33 s/^/#/' /system/etc/audio_policy.conf;
sed -i '34 s/^/#/' /system/etc/audio_policy.conf;
sed -i '35 s/^/#/' /system/etc/audio_policy.conf;
sed -i '36 s/^/#/' /system/etc/audio_policy.conf;
sed -i '37 s/^/#/' /system/etc/audio_policy.conf;
sed -i '38 s/^/#/' /system/etc/audio_policy.conf;

After flashing a ROM, TWRP doesn't give any errors about it in tmp/recovery.log, but it doesn't change anything in audio_policy.conf.

When I run them manually through terminal in adb shell, they work.

Here is my entire addon.d script, named 70-customize.sh, and the sed commands are at the bottom of it:

EDIT: Solved

Does anyone have any way that I can make this thing work?