Hello, I am developing routers for over 5 years and have developed TL-WR1043ND, ASUS RT-N13ub1, Netgear Routers, Mercury routers with openwrt and dd-wrt.
I have mainly implemented captive portal hotspot solutions for coffee shops, bars, metro, bank, bus stops, etc.
I have enough experience knowledge about this, and I can give you the perfect result that you want.
Thanks. waiting your reply kindly~