I've never had ANY bead leaks until the E07. After nearly a year and close to 10k miles, my front started leaking a few psi/day, from the rim/ bead area.
Maybe coincidence, but that same tire kicked my butt going on. I could NOT get air in fast enough to get the bead to seat. I ended up getting it bead blasted on at a tire place. I put a lot of soap and water on that bead before giving up.
What's weird to me is that it was bulletproof for so long before it developed the leak(s). There was still a few thousand miles left on the tread. I got sick of having to air up every time I rode and changed it.
FWIW, my rims are total shit - I have lots of little dings and grooves from tire spoons. Wen the E07 came off, there was corrosion on the beads, too. I assumed it was from the excess soap and water I used at installation.
I sanded my beads back to bare metal to level out those those dings and grooves, then spray painted them black again. New set of tires has been fine for about two thousand miles. Last week my back tire started leaking, but I haven't checked whether it's a rim issue or not.
TLDR version: don't be afraid to hand-sand the beads on the rim with 120-ish grit or higher. You'd have a hard time damaging them by hand. Paint is a good defense against corrosion, and even if you do a crappy job painting, it's hidden inside the tire. I've also seen corrosion, but (maybe coincidentally), the only time I saw it was months after mounting a tire with a LOT of soap and water. After that, I bought some tire lube.