I believe it worth it as it uses an older kernel and different other older version of packages like dnsmasq that should use less RAM memory.
If you have a serial console it would help me very much to paste the brick boot log on the thread [Testing] lede-17.01 security backports for 4/32 devices
thanks
If we come back on topic maybe you should try using 18.06.8 - https://downloads.openwrt.org/releases/18.06.8/targets/ar71xx/generic/openwrt-18.06.8-ar71xx-generic-tl-wr842n-v2-squashfs-sysupgrade.bin or better build you own based on your needs https://openwrt.org/docs/guide-user/additional-software/imagebuilder (still recommend 18.06.8)
see also https://openwrt.org/docs/guide-user/additional-software/saving_space && https://openwrt.org/faq/build_image_for_devices_with_only_16_32mb_ram