This won't help new users, but for people who own a previous release (before it turned into a "modern app") you can still download 1Password v4 for Windows.
Enpass doesn't seem to support multiple vaults at all though...
However, on my Surface Pro 4 I use Edge, because it supposedly uses less power than Chrome.
If I've understood the 1Password forums correctly, the Edge integration that they are working on will only be in the subscription version. Those of us staying on 4 will be stuck with manually looking up passwords in 1Password.