This is the most treasured and sought after feature for all DX lovers using Enigma2 for many years now.
I have already seen tests with both OSmio (Availink) and SF8008 (Silabs) tuners and in both cases no lock values are comparable to PC cards, so that should indicate that at least initially these tuners can show signals below lock with no visible issues.
I am curious if the same can happen for gfutures drivers on Silabs (HD51 etc).
It is definitely worth a trial and error, even with a function that can enable this feature in the tuner settings. For what it's worth, tuner/driver combos that support it will only benefit from this feature.
If I am not mistaken, this was already possible with some Dreamboxes only on their closed source images.