Hi and welcome to the forums NealStephenson,
About running it on a Linksys WRT-54G, I guess it’s plausible if you SDCard mod the router and shove DD-WRT onto it. But, I honestly have no idea of the coding behind the stratum_proxy but it would actually be a very good implementation if it could be compiled, effectively, for unix builds. Especially microbuilds such as custom firmware for routers.
I pre-appologise I can’t really give you a definitive answer, but I’d guess it’s very plausible. It’s also nice to see someone around with a bit (or a lot) of knowledge and understanding too.~ ^^