This is actually the first time I'm hearing about single electron theory, but I feel validated now that I'm learning about it. I have for a long time believed that the universe is made of a single photon, since photons exist outside of time. Then, if electrons are made of a "pair" of entangled photons, since every photon is the same photon, it would follow that every electron is also the same electron. And one could assert that quarks are just entangled electrons and positrons in various ratios and combinations. Which in my mind leads to the conclusion that all of time and space and matter doesn't actually exist and we are just imaginary mathematical figments.