Is there a trick to get artificial note offs to work?

[VirtualVirgin]

In this case, I have ignored the incoming note offs, and have new ("artificial") note offs generated.
The readout in the subsequent Event Logger looks good:

Each note on is getting a note off where I want it on the Event Logger, but the note off messages aren't actually functioning to kill the note in the following Sine Wave Generator. All three notes are still ringing (60, 67, 72).

Does the "artificial" note off message have some special status I need to change in order for it to get recognized as a normal note off?

[VirtualVirgin]

So it seems the artificial note offs do not work unless you use
Message.sendToMidiOut();

I find this a bit confusing as other messages work properly to pass on to subsequent modules in the rack. Why would the artificial note offs be treated differently from that?

In the Event Logger they now appear to "pair" (the brackets on the left side) with the note ons that precede them at the same note number:

I thought the
Message.sendToMidiOut();
was essentially just routing a copy any MIDI appearing at that point to go to the output of the plugin, so I'm not clear on why that would be effecting the internal relationship of note on to note off messages. Where exactly were the note offs going before that would make them appear on the Event Logger, but not have them usable?