Awesome Window Manager - Open Chromium Developer Tools on Different Screen Than Chromium
I managed to work around the issue by targeting the windows role instead of the name. I also made the rules more succinct by using rule_any for the identical browser rules.
awful.rules.rules = {
{ rule = { },
properties = { border_width = beautiful.border_width,
border_color = beautiful.border_normal,
focus = awful.client.focus.filter,
keys = clientkeys,
buttons = clientbuttons } },
{ rule = { class = "URxvt" },
properties = { tag = tags[2][1],
size_hints_honor = false } },
{ rule_any = { class = { "Chromium-browser", "Firefox", "Opera" } },
properties = { tag = tags[1][1] } },
{ rule = { class = "Chromium-browser", role = "pop-up" },
properties = { tag = tags[3][1] } }
}