Sort by listing time vs. (un)freeze

I believe I just noticed something that imo could use some tweaking.

Simplified, I have a saved trade search that has been empty for some time now.
It suddenly stopped being empty today or yesterday.
The listing included now was listed "4 months ago".

While I can't be certain, an educated guess would suggest that the listing in question has simply been frozen for some time and was now unfrozen. As a result, it was hidden for however long and post-unfreeze started showing up again.

In this particular case, it doesn't matter much because it is currently the only result and hence obvious. However, looking at it, that behavior would create a rather undesirable possible scenario for trade listings that are more populated and often re-searched (such as renewed sunders):

E.g.:
- User A is looking for a more common item, let's say a Renewed Cold Rupture
- User A wants specific stats on that item
- User A hence starts a search for Renewed Cold Rupture, sorts results by listing time, checks each one and because none of those currently on offer have the right stats bookmarks the search and tries again the next day (and the next and ...), checking only the new additions (hence the sort by listing time) as the existing 4 pages or however much have already been checked
- User B has the exact Renewed Cold Rupture user A is looking for
- User B had that Renewed Cold Rupture listed for say 3 weeks before user A started looking
- A day before user A started looking however, user B froze his trades and went on a short trip
- A couple days after user A started looking, user B returns from his trip, unfreezes his trade and proceeds as normal

-> By the time B unfreezes (and hence makes visible again) his trade, user A will never see it as it'll be hidden somewhere in multiple pages of "I already checked all of these" and won't pop up as a new addition at the top, thanks to listing time being quite some time ago, even though it only became visible again that same day.

The more folks start using the freeze function, the more common that scenario would become. Especially now that we have an auto-freeze replacing expiration, meaning we're potentially in the future looking at some very dated trades returning from the grave.

One possible approach would be to add a "last unfrozen" time stamp that could either be sorted by specifically (which would then basically add a 2nd bookmark but cover both bases) or a trade's listing time could be updated to the time of last unfreeze when it is unfrozen, effectively making "listing time" more of a "visible since". The latter would have the advantage of leaving those searching with a single bookmark but the disadvantage of "freeze -> unfreeze" effectively becoming a "push to top" manipulation for those searches. Though that disadvantage might end up rare/irrelevant, thanks to the unfreeze throttle/timer after a manual freeze effectively preventing intentional abuse.
Another option might be a "recently unfrozen" filter for searches that essentially filters the results down to only showing those that have been unfrozen in the last say 24 or 48 hours. The same bookmarked search in the above example would then simply be opened (to get the new listings) and then in a 2nd step the "recently unfrozen" filter would be checked and applied to double-check for "new" unfrozen ones in a less convoluted results list.
Or in a perfect world, to cleanly cover everything, a filter to only show trades that the user has never looked at. That'd essentially remove the entire need for sorting by listing time or unfreeze time or any of that as all results could simply be limited to only those trades that the searching user has never opened before, meaning everything they already looked at is automatically removed from the results, regardless of listing time or any freezing/unfreezing.