[OnePlus 3 Guides, News, & Discussion] Phaech4x:
TL; DR HydrogenOS, OxygenOS, LineageOS and most of custom ROMs for oneplus3 has ifaa and soter binary blobs for fingerprint/iris authorization which is used for confirm payment in Alipay and WeChat Pay the most popular mobile payment Apps in mainland China, in case you don't use them, just want to get rid of them, or having privacy or security concern, you can just flash this zip in TWRP to deblob them (require firmware OxygenOS 9.0.2+, system-as-root). You probably need to flash it along with your ROM each time you install a new ROM or update existing one.

IFAA is used by Alipay, Tencent soter is used in WeChat Pay.

Those blobs and proprietary files (including IFAAService and SoterService apk) are used for biometric authentication during confirm payment in Alipay and WeChat Pay (usually by touching fingerprint censor to avoid typing password each time during confirm payment, they are disabled by default in those Apps and password authentication works without them)

This zip remove binary blobs alipay.* and soter.* from modem partition (which comes from NON-HLOS.bin the FAT filesystem image in official OxygenOS zip), IFAAService and SoterService apk and related proprietary libraries.

IFAA Manager (org.ifaa.android.manager) is open source, this zip does not remove IFAA Manager because it's probably included in BOOTCLASSPATH and removing them will cause lags on app start. You may ask ROM maintainers to remove them at compile time to remove them.

faceapp.* in modem and vendor/lib/libmmcamera_facedetection_lib.so in system also looks suspicious, but this zip does not remove it. You can edit it to suit your needs.

Tested on firmware from OxygenOS 9.0.6, LineageOS 17.1 (unofficial), TWRP 3.3.1-0

META-INF/com/google/android/updater-script

assert(getprop("ro.product.device") == "OnePlus3" || getprop("ro.build.product") == "OnePlus3" ||
getprop("ro.product.device") == "oneplus3" || getprop("ro.build.product") == "oneplus3" ||
getprop("ro.product.device") == "OnePlus3T" || getprop("ro.build.product") == "OnePlus3T" ||
getprop("ro.product.device") == "oneplus3t" || getprop("ro.build.product") == "oneplus3t" || abort("E3004: This package is for device: OnePlus3,oneplus3,OnePlus3T,oneplus3t; this device is " + getprop("ro.product.device") + "."););
assert(op3.verify_modem("2019-05-11 00:00:51") == "1" || abort("This package is for modem firmware from OxygenOS 9.0.2 or newer"););

ui_print(" ");
ui_print("## Deblob alipay ifaa and tencent soter ##");
ui_print("## for OnePlus 3 and OnePlus 3T ##");
ui_print("## this won't remove org.ifaa.android.manager ##");
ui_print("## because it's may included in BOOTCLASSPATH ##");

ui_print("Mounting system and modem...");
run_program("/sbin/toybox", "mount", "/system");
run_program("/sbin/toybox", "mount", "/dev/block/by-name/modem", "/system/system/vendor/firmware_mnt");

ui_print("Deblob alipay from modem...");
delete("/system/system/vendor/firmware_mnt/image/alipay.b00");
delete("/system/system/vendor/firmware_mnt/image/alipay.b01");
delete("/system/system/vendor/firmware_mnt/image/alipay.b02");
delete("/system/system/vendor/firmware_mnt/image/alipay.b03");
delete("/system/system/vendor/firmware_mnt/image/alipay.b04");
delete("/system/system/vendor/firmware_mnt/image/alipay.b05");
delete("/system/system/vendor/firmware_mnt/image/alipay.b06");
delete("/system/system/vendor/firmware_mnt/image/alipay.mdt");
ui_print("Deblob soter from modem...");
delete("/system/system/vendor/firmware_mnt/image/soter64.b00");
delete("/system/system/vendor/firmware_mnt/image/soter64.b01");
delete("/system/system/vendor/firmware_mnt/image/soter64.b02");
delete("/system/system/vendor/firmware_mnt/image/soter64.b03");
delete("/system/system/vendor/firmware_mnt/image/soter64.b04");
delete("/system/system/vendor/firmware_mnt/image/soter64.b05");
delete("/system/system/vendor/firmware_mnt/image/soter64.b06");
delete("/system/system/vendor/firmware_mnt/image/soter64.mdt");

ui_print("Remove proprietary files of ifaa from system...");
delete_recursive("/system/system/priv-app/IFAAService");
delete("/system/system/lib64/vendor.oneplus.hardware.ifaa@2.0.so");
delete("/system/system/vendor/bin/hw/vendor.oneplus.hardware.ifaa@2.0-service");
delete("/system/system/vendor/etc/init/vendor.oneplus.hardware.ifaa@2.0-service.rc");
## removing org.ifaa.android.manager will cause lags on app start if it's included in BOOTCLASSPATH
# run_program("/sbin/sed", "-i", "s#:/system/framework/org.ifaa.android.manager.jar##", "/system/init.environ.rc");
# delete("/system/system/framework/org.ifaa.android.manager.jar");
# delete("/system/system/framework/boot-org.ifaa.android.manager.vdex");
# delete("/system/system/framework/arm/boot-org.ifaa.android.manager.art");
# delete("/system/system/framework/arm/boot-org.ifaa.android.manager.oat");
# delete("/system/system/framework/arm/boot-org.ifaa.android.manager.vdex");
# delete("/system/system/framework/arm64/boot-org.ifaa.android.manager.art");
# delete("/system/system/framework/arm64/boot-org.ifaa.android.manager.oat");
# delete("/system/system/framework/arm64/boot-org.ifaa.android.manager.vdex");
ui_print("Remove proprietary files of soter from system...");
delete_recursive("/system/system/app/SoterService");
delete("/system/system/vendor/bin/hw/vendor.qti.hardware.soter@1.0-service");
delete("/system/system/vendor/etc/init/vendor.qti.hardware.soter@1.0-service.rc");
delete("/system/system/vendor/lib64/hw/vendor.qti.hardware.soter@1.0-impl.so");
delete("/system/system/vendor/lib64/vendor.qti.hardware.soter@1.0.so");

show_progress(1, 5);

ui_print("Unmounting...");
run_program("/sbin/toybox", "umount", "/system/system/vendor/firmware_mnt");
run_program("/sbin/toybox", "umount", "/system");

ui_print("## Finished deblob alipay ifaa and soter ##");
ui_print(" ");

To check if you have successfully deblob and removed these files, just check if these files are been removed in any file manager with root on Android, or run the following command in a Terminal Emulator App or adb and check the output.

OnePlus3:/ # find /system -iname "*ifaa*"
/system/framework/arm64/boot-org.ifaa.android.manager.art
/system/framework/arm64/boot-org.ifaa.android.manager.oat
/system/framework/arm64/boot-org.ifaa.android.manager.vdex
/system/framework/org.ifaa.android.manager.jar
/system/framework/arm/boot-org.ifaa.android.manager.art
/system/framework/arm/boot-org.ifaa.android.manager.oat
/system/framework/arm/boot-org.ifaa.android.manager.vdex
/system/framework/boot-org.ifaa.android.manager.vdex
OnePlus3:/ # find /system -iname "*soter*"
OnePlus3:/ #

UPDATE:

Rewrote the post to reduce the mess. Thanks [MENTION=4405529]nvertigo67[/MENTION] for pointing out BOOTCLASSPATH and performance drop issue when ifaa manager was removed.