This may be expected behavior?
I enabled the display of time zone offsets in the Metadata panel, and mostly got the expected results (thank you, Mario).
However I see one unexpected result: Photos I took yesterday show something like 'Yesterday at 4:28:23 PM' w/o the time zone. I assume this is because the new change is overwritten by the 'yesterday' text handling?
This is the indented behavior. It's special for images taking "today" and "yesterday".
I did not touch this since it works that way since IMatch 5, I believe.