Yes, I did that already. However, to save space in flash/RAM, and because I do not need the “enhanced” features of wpad, would like to “untick” wpad and “tick” wpad-mini. Not so easy, though.
I also need to edit Makefile for squid, to save RAM and to drop IPv6 features for same reason.
Used to do all this on official openwrt/LEDE when developing custom firmware for special products.
For the actual one, the MIFI-hardware seems very suitable (battery and 3g integrated) for unattended operations.