The item has been moved in our feedback portal here: Ability for Salesforce connector to address different urls than the hardcoded https://login.salesforce.com'
The status is still "Not Done" which means that there is no progress on it.
The main reason is that this did not gather much votes, so I can strongly advise to cast one, so it could be implemented in some of our upcoming releases.
I am sorry for the inconvenience this is causing you.
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