In a large lot of devices that I bought last year, I got two of these, IRlinc Transmitter. I did some searching and found the discussions below on the forum, from 2017. The two units that I have are also release 4A. Now here's the interesting part: The guy I got them from (and a bunch of other Insteon devices) had a ISY994i, and he told me that these IR transmitters worked with it. The sticky tape on the ends of the emitters has been torn away, so these have clearly been used. Yet the discussions I see, including the discussion below, say that they need firmware 1.3 to work (with the ISY994i at the time). I'm trying it out on a test Polisy. I can link the module just fine, using either link method, and learning a IR command seems to go through ok, but the device nodes never appear.

Seeing that the discussion from 2017 includes a few still active members here ( @Brian H and @larryllix ) , I thought I'd ask whatever became of it? Even more tantalizing is that @Chris Jahn and @stusviews say they got it working with v4A, though that was with a ISY994i. But all the prompts are there and look the same, even in 6.0.4 on the Polisy.

The only thing I remember about those pieces of junk is the unit I received had the IR sender was wired in reverse polarity and I could never get it to work properly. I could not get passed the memorize the IR codes I tried to program it with, and then ISY would not recognize it properly.

When I tried to send it back under Insteon's warranty, they replied, sure..not problem but the $50 CAD cost to return it for warranty services was almost the cost of a new unit. Poor warranty for a newly purchased device. Buh-bye old Insteon failure. (Glad to see new blood there)

Garbage.
As IR was dying very quickly I attempted to find other ways and other equipment that didn't use IR, or also supported WiFi control.