I have no idea what that amount of the extract would do for you. Presumably, not much. I don't think it would add much in the way of maltiness, either. It may be to "wake" the yeast back up, but I don't think that amount of it would even do that in any significant way.
I've never made a tea for this purpose, but I have dropped a couple of hop pellets in a tea infuser and poured boiling water on them, a 10 minute steep made a quite bitter tea. I think you'd be fine without the extract.
This will probably produce a different hop character from what you would get from having enough hops in the main boil. The proteins in the boiling wort coagulate around some of the hop solids and drop out of suspension, and the hop oils will coat yeast cells and flocculate out during fermentation. You'll probably want to pour several 2-3oz tasting glasses, carefully measure your hop tea, and add it to each glass in varying amounts. The amount to add to the full batch should scale linearly (i.e. 1 Tablespoon in a 12oz sample would equal around 50 Tablespoons for a 5 gallon batch).