This won't impact the underlying data at all, but keep your eye on bandwidth usage by queries.
This won't impact the underlying data at all. But it WILL mean that every query will operate against the totality of data across both sites. Some queries can incur some significant bandwidth usage to the remote indexers.
With both webservers pointed at all the indexers the scheduled searches/alert scripts will fire on all data twice, generating truly duplicate results. We recommend an overwatch setup for this type of topology.
If there are alerts that should span both sites those scheduled scripts should run on the overwatch webserver.
RE TLS - the webserver to indexer connections are not TLS enabled, we treat those connections as trusted and high bandwidth. The goal for those links is low latency and low CPU overhead above all else.