[Samsung Galaxy M21 Guides, News, & Discussion] matkali:
Build Props Tweaks [For both rooting method (System & Systemless)]

I am NOT responsible for bricked devices, destroyed SD cards or any
damage that may happen to your device.

We need to add this code to the end of file "/system/build.prop"

I will add complete information in the future about these codes!

I try these in Lineage OS 17.1 and give good results! :D

To begging these tweaks:

1- Enable adb from developer options.

2- In recovery mode mount System partition and connect your USB to your computer!

3- Open your computer terminal and type this (to pull(download) the file "/system/build.prop" to your Desktop):

adb pull /system/build.prop ~/Desktop/build.prop

4- Now come to your Desktop and first take a backup from this file then open the file "build.prop" with text editor and add all below codes to the end of file "build.prop" then save it! (don't try to edit other lines!)

#----------------------------------
# Start
#----------------------------------

# Audio enhancer

persist.audio.fluence.mode=endfire
persist.audio.vr.enable=true
persist.audio.handset.mic=digital
af.resampler.quality=255
mpq.audio.decode=true

#----------------------------------

# Call delay

ro.telephony.call_ring.delay=800

#----------------------------------

# Video acceleration enabled

video.accelerate.hw=1

#----------------------------------

# Wifi scaning rate [every 60 --> 1 scan / min]

wifi.supplicant_scan_interval=180

#----------------------------------

# Deeper sleep/better battery life [for extrimmly power save] [kills all background apps]

ro.ril.disable.power.collapse=1
# pm.sleep_mode=1

#----------------------------------

# Improves audio and video recording quality

ro.media.enc.hprof.vid.fps=65
ro.media.enc.hprof.vid.bps=8000000

ro.media.capture.maxres=8m
ro.camcorder.videoModes=true

#----------------------------------

# Picture Quality Enhancer

ro.media.enc.jpeg.quality=100
ro.media.dec.jpeg.memcap=8000000

#----------------------------------

# Disable Boot Animation [for Enable set 0]

debug.sf.nobootanimation=1

#----------------------------------

# Disable Camera Sound

ro.camera.sound.forced=0

#----------------------------------

# Better Scrolling

ro.min_pointer_dur=8
ro.max.fling_velocity=12000
windowsmgr.max_events_per_sec=60

#----------------------------------

# Disable strict mode checking

persist.android.strictmode=0

#----------------------------------

# Remain launcher in memory
ro.HOME_APP_ADJ=1

#----------------------------------

# Disable usb debugging popup in notification

# persist.adb.notify=0

#----------------------------------

# Proximeter delays

ro.lge.proximity.delay=25
mot.proximity.delay=10

#----------------------------------

# media enhancer [codecs]

ro.media.dec.aud.flac.enabled=1
ro.media.dec.aud.wma.enabled=1
ro.media.dec.vid.avi.enabled=1
ro.media.dec.vid.wmv.enabled=1
ro.media.dec.aud.wma.enabled=1
ro.media.dec.aud.mp3.enabled=1
ro.media.dec.vid.mp4.enabled=1
ro.media.dec.aud.flac.enabled=1
ro.media.dec.vid.H.264.enabled=1
ro.media.enc.aud.flac.enabled=1
ro.media.enc.vid.H.264.enabled=1
ro.media.enc.aud.wma.enabled=1
ro.media.enc.vid.wmv.enabled=1
ro.media.enc.aud.mp3.enabled=1
ro.media.enc.vid.mp4.enabled=1

#----------------------------------

# Improved performance

debug.performance.tuning=1

#----------------------------------

# DNS Servers [Quad9 & Cloudflare]

net.dns1=9.9.9.9
net.dns2=149.112.112.112
net.dns3=1.1.1.1
net.dns4=1.0.0.1

net.wlan0.dns1=9.9.9.9
net.wlan0.dns2=149.112.112.112
net.wlan0.dns3=1.1.1.1
net.wlan0.dns4=1.0.0.1

net.eth0.dns1=9.9.9.9
net.eth0.dns2=149.112.112.112
net.eth0.dns3=1.1.1.1
net.eth0.dns4=1.0.0.1

net.wcdma.dns1=9.9.9.9
net.wcdma.dns2=149.112.112.112
net.wcdma.dns3=1.1.1.1
net.wcdma.dns4=1.0.0.1

net.hspa.dns1=9.9.9.9
net.hspa.dns2=149.112.112.112
net.hspa.dns3=1.1.1.1
net.hspa.dns4=1.0.0.1

net.lte.dns1=9.9.9.9
net.lte.dns2=149.112.112.112
net.lte.dns3=1.1.1.1
net.lte.dns4=1.0.0.1

net.ltea.dns1=9.9.9.9
net.ltea.dns2=149.112.112.112
net.ltea.dns3=1.1.1.1
net.ltea.dns4=1.0.0.1

#----------------------------------

# Better Network Signals

persist.cust.tel.eons=1
ro.config.hw_fast_dormancy=1

#----------------------------------

# Better call voice quality

ro.ril.enable.amr.wideband=1

#----------------------------------

# Faster streaming videos

media.stagefright.enable-player=true
media.stagefright.enable-meta=true
media.stagefright.enable-scan=true
media.stagefright.enable-http=true
media.stagefright.enable-rtsp=true
media.stagefright.enable-record=false

#----------------------------------

# Disables built in error reporting

profiler.force_disable_err_rpt=1
profiler.force_disable_ulog=1

#----------------------------------

# Disables kernel error checking

ro.kernel.android.checkjni=0
ro.kernel.checkjni=0

#----------------------------------

# Disable Logcat

logcat.live=disable

#----------------------------------

# Disables sending of usage data

ro.config.nocheckin=1

#----------------------------------

# Boost Booting Speed & hibernate mode

ro.config.hw_quickpoweron=true
persist.sys.shutdown.mode=hibernate

#----------------------------------

# Very fast reboot

persist.sys.purgeable_assets=1

#----------------------------------

# Disables locating

ro.com.google.locationfeatures=0
ro.com.google.networklocation=0

#----------------------------------

# Net speed enhancer[tcp buffersize]

net.tcp.buffersize.default=6144,87380,110208,6144,16384,110208
net.tcp.buffersize.edge=6144,26280,35040,6144,16384,35040
net.tcp.buffersize.evdo_b=6144,262144,1048576,6144,262144,1048576
net.tcp.buffersize.gprs=6144,8760,11680,6144,8760,11680
net.tcp.buffersize.hsdpa=6144,262144,1048576,6144,262144,1048576
net.tcp.buffersize.hspa=6144,87380,262144,6144,16384,262144
net.tcp.buffersize.lte=262144,524288,3145728,262144,524288,3145728
net.tcp.buffersize.umts=6144,87380,110208,6144,16384,110208
net.tcp.buffersize.wifi=262144,524288,1048576,262144,524288,1048576

#----------------------------------

# For Sensor Sleep Control
ro.ril.sensor.sleep.control=1

#----------------------------------

# DHA tunning
ro.config.dha_tunnable=1

#----------------------------------

# Faster Boot-Animation FPS
# boot.fps=20

#----------------------------------
# END
#----------------------------------

5- Now we must push(upload) new file "build.prop" by typing this command in your terminal:

adb push ~/Desktop/build.prop /system/build.prop

:);)

If you have a problem with these tweaks use backup file to restore your first file "/system/build.prop"

If you have any suggestion to improve this thread please tell me!