There are three statements which look rather similar but mean different things:
A) "Officer Vai will purchase only bandit scalps" - meaning she will purchase nothing except bandit scalps.
"Only Officer Vai will purchase bandit scalps" - meaning no-one else will purchase bandit scalps (but saying nothing about whether or not Vai might also deal in other items).
C) "Officer Vai will only purchase bandit scalps" - meaning she refuses to do anything else with bandit scalps (such as sell them).
Observed behaviour: the patch log says C (it's a direct quote), but that was already true before the patch (and still true after the patch). What has been implemented in the patch is both A and B, even though that's not what the patch log says.
Expected behaviour: assuming that the idea was to prevent the sale of other miscellaneous items at the advantageous prices offered by Vai, then A should have been implemented (and the patch log should have said A). Implementing B in addition is surely an error, since bandit scalps continue to drop (and continue to be shown as having a value) but there's now nowhere you can sell them after Vai leaves (or before she arrives), so they're then garbage in spite of having a value shown. (In contrast with this, other garbage items, such as cursed scrolls, are shown with nil value.) It used to be the case that you could also dispose of bandit scalps in a couple of other places (such as Feldepost's Inn), although for less than Vai would pay, and that behaviour ought to be restored.