I use this on mine.

I think it’s this one: BAFX Products IR Repeater -... https://www.amazon.com/dp/B009ZGK6QS?ref=ppx_pop_mob_ap_share

It’s not anything special, but it’s worked pretty well since I got it in 2017.

I used a simple mono headphone plug from the harmony hub to an IR repeater box. That boosts the signal from the harmony hub and repeats it to upto 12 devices. It’s overkill, since I think I only have 4 devices currently, but I guess that gives me room to expand.

The IR repeater I have isn’t anything special, but it’s this one:

BAFX Products IR Repeater -... https://www.amazon.com/dp/B009ZGK6QS?ref=ppx_pop_mob_ap_share

Are you just talking about a repeater for the remote control? If so, this is the one I use for my UVerse box and other equipment (all of which is in a cabinet):

BAFX Products (Infrared) IR Remote Control Extender or IR Repeater Kit - Control 1 to 8 Devices (Expandable to 12!) https://www.amazon.com/dp/B009ZGK6QS

If your closet is more than a few feet away, you’ll need a Cat5 extender - you can find those links on the product page.