no i just meant i'm using zram function already available.. haven't improved it or anything. so my comment was kinda offtopic for this thread..
i have two android devices that i use zram on. one is a armv7 msm8974 phone with 2gb ram on android 8.1 (LG G2), the other is an arm64 sdm429 tablet also with 2gb ram on android 11 (Samsung Galaxy Tab A 8.0 2019). i frequently run termux and firefox/kiwibrowser together.
btw this Galaxy Tab A i have is one of those devices where the manufacturer decided to include armv7 kernel on a 64bit device. thankfully the bootloader is 64bit capable, and even the stock rom in one specific region is in 64bit, so i'm able to use 64bit in mine.
the android build system is actually not necessary to modify the android kernel. the kernel zImage/Image.gz can be built by simply getting the android toolchain (arm-eabi-4.9 for me) and compiling the kernel thru linux standard process (export ARCH=arm; export CROSS_COMPILE; make defconfig; make) and manually replacing the kernel in boot.img using unpackbootimg and mkbootimg.