We're in the same boat and at a complete loss, would love to see this be able to happen.

We want a view to show all tickets within a certain breach window (e.g. less than three hours till breach) but also still show tickets in that view if they have already breached as well. Unfortunately this is impossible since "Hours until breach" must be an ALL condition and once the ticket breaches, it no longer technically has a time until breach number since the breach event has passed. The effect it's having is that now after the ticket breaches, it vanishes from the view. Any potential solution to this is cumbersome and has downsides:

Use an automation to tag tickets once they hit the breach window and remain tagged after breach, therefore allowing us to remove the "Hours until..." condition from the view and just pull by tag. Downside is that if we use an automation, since they only run once/hour, there's the potential for the tag to not be applied for a full hour after the ticket should be in the countdown window if it misses its first opportunity to run.
Use the API to tag these tickets in real time. For high-volume Zendesk users who occasionally hit the API rate limit momentarily, this runs the risk of having some tickets miss getting tagged.

We can't use any alternative hours logic (e.g. hours since creation, hours since update, due date) because in all those instances there will be a cutoff for which we also want to pull tickets after that cutoff as well, no matter where that clock is ticking from.