bjarnco32

Search on Google nalang po kung hindi makapag PM, gamitin itong search terms "braveheartleo alternative custom firmware for prepaid home wifi"

There is no OpenWrt build for FX-ID3E, only for FX-ID3. There may be some changes between the two under the hood.

Send me a PM here po.

Try to reflash the firmware using the bootloader.

Yes po, captive portals are installable packages in OpenWrt. You just need to make sure that space requirements are sufficient before installing.

FX-ID4, it has a USB3 port, external antennas, and better hardware spec. You can install a captive portal in OpenWrt.