I tested this on current master (3.7 beta-ish) and I am able to create new statuses and have them appear in the Status dropdown when editing an item.
I verified that it does pay attention to whether or not the status is OPAC-visible and whether or not the status is holdable.
I verified that if I place a hold (either title level or item level) and scan that item in, it recognizes the hold and routes it to the holds shelf.
And the bad:
However, the status does NOT appear to be recognized by the process that populates the Holds Pull List. (Thanks to jpringle for mentioning that in comment #8.)
The good news:
I tested this on current master (3.7 beta-ish) and I am able to create new statuses and have them appear in the Status dropdown when editing an item.
I verified that it does pay attention to whether or not the status is OPAC-visible and whether or not the status is holdable.
I verified that if I place a hold (either title level or item level) and scan that item in, it recognizes the hold and routes it to the holds shelf.
And the bad:
However, the status does NOT appear to be recognized by the process that populates the Holds Pull List. (Thanks to jpringle for mentioning that in comment #8.)