It would be great to have lookup time displayed somewhere (in tiny fonts, obviously). Once the lookup time is slower than - let's say - 500 ms, then the results could be displayed in red. That's why users would quickly know that something doesn't work properly and the TM needs to be reorganized, moved to a faster disk etc. In general there are numerous things, which can go slowly when files are processed, but TM lookup is the one, which has a very important impact on the work of many users. Some of them simply accept the fact that lookup takes even >1 sec without investigating the issue or even without being aware that their config is not working as designed.