Note that the trade-off here is a making the subscriptions less robust, i.e. more likely to break completely. Our initial decision here is to make the subscriptions as robust as possible so people can rely on the feature, with the downside of possible conflicts as described here being probably quite rare.

A better solution would be to embed more accurate timestamps (i.e. with seconds) via T230653 to reduce the chance of a conflict. The subscriptions database has been designed to handle the more accurate timestamps.

For reference, the current behavior is documented at https://www.mediawiki.org/wiki/Extension:DiscussionTools/How_it_works#Tracking_topics.

At least, all related talk pages should be displayed on Special:TopicSubscriptions.

T306373: Update Special:TopicSubscriptions to use permalinks would allow this.