I was going to go with pfSense for that feature. Do you think it makes sense?
I did tried dd-wrt for this same purpose, the interface is much better, it is very flexible as openwrt, but I couldn't put my wifi on client and AP mode at the same time and I needed to connect to one of my WAN using wifi because that modem is not close enough yet.
if you have older x86 hardware, it's hard to top pfsense.