I've used hop shots.
They work fine in the boil with no wort wasted in the bottom of the kettle.
They do leave a resin "scum line" in the kettle at the boil level.
Although I've not used them to make a hop tea.
PSA- DON'T DO THIS ! ! !
One time after squirting the vial into the kettle, there was a little drop on the end of the syringe and I thought what the heck and put it to my tongue.
Man was that the WRONG thing to do, my tongue touched the roof of my mouth, now I had it on my tongue and the roof of my mouth, I rinsed to no avail, got a paper towel, wiped the roof of my mouth and my tongue, let me tell you the taste was overwhelming for hours, the wiping didn't help enough, although it did wipe out the little bead that was in my mouth. Very bad move. Lesson learned.