Not best option, because
1. Electrum wallet isn't scalable (one of the reason is usage of JSON to store the information).
2. Electrum server maximum request for each user.
Can you analyze the first reason a little bit more?
@Coding Enthusiast explained it in detail.
But obviously it's not efficient since it's written on pure Python and JSON doesn't scale well.
The lack of efficiency is not about the language, it is because
the entire file is read and written each time instead of partial read/writes which can't really scale. It woks well for small sizes which is why there is only a handful of complaints so far.
But you are right JSON itself doesn't scale well.
Besides the above, he'll expose all these addresses to electrum nodes, which isn't recommended for privacy reasons, especially if they're clients' addresses.
I agree, but
1. It broke assumption request from 1 IP is for single people.
2. OP already "invade" client's privacy.