Nowadays those 4/32MB routers are best for just extending signal range.
Yes, this is what I am using this for 
For IPTV, though, I seem to require igmpproxy (see IGMPv3 (igmpproxy) / Telekom MagentaTV / TP-Link Archer C2600), which has 16 kB and no dependencies apart from libc (which the image should have for luci). Any chance to fit this into the next build? I am using a TP-Link TL-WR841N/ND v9.
Edit: I was able to compile myself on WSL, which works great. Here's short instructions for anyone wanting to try this themselves:
git clone https://git.openwrt.org/openwrt/openwrt.git
cd openwrt
git checkout v19.07.7
./scripts/feeds update -a && ./scripts/feeds install -a
wget https://openwrt.ashus.net/19.07.7-targets-ath79-tiny-luci/config -O .config
make menuconfig # select TP-Link TL-WR841N/ND v9, add igmpproxy, save, exit
make -j4 # build with 4 cores