Update: It's done now (bottled a week ago). I haven't gotten external opinions on it yet but I think it turned out a good beer, but you probably wouldn't be able to pinpoint tea as an ingredient if you didn't know. It probably does give a bit of extra depth of flavour, but it's not distinctly tea-like. I'm saving the last bottle of my 1st batch to do a side-by-side comparison with this, ideally with someone else who would be big into beer.

Next time I do a tea beer I'll probably use 10 g/l and let it steep for longer, maybe till the end of cooling. Maybe to be on the safe side I should tone down the bittering hops to compensate. I wish I knew how to account for the tea's bitterness in the IBU calculation.